Executive Summary: This doesn't do much for origin of man; that would require observation of a simple organism developing complicated traits. Bonus points if it's reproducible. Not all creationists believe the same thing; most of them will be unswayed by this.
This only really addresses a single school of thought in creationism. I'll discuss it as I point out some interesting things I noticed.
First, you have to decide how narrow or broad you want the phrase "evolution" to be. In the broadest sense, evolution is taken to mean "genetic code changes in a fashion that is repeated via reproduction"; most people I know are more comfortable with calling this "adaptation". The reason for this is they prefer to reserve evolution for the generation of new species, and in general a requirement for being a new species is the inability to interbreed with the previous species and producing fertile offspring. There's plenty of adaptations within our species: people who live in higher altitudes have larger chests in order to hold larger lungs, people in climates with more sunlight have darker skin, etc. Still, they are able to interbreed with other humans and create fertile offspring and therefore they are part of the same species. However, bacteria are a difficult case to classify; they reproduce asexually. This makes it hard to base a definition of species off of interbreeding, so I'm not certain how well an argument that this is adaptation vs. evolution will hold.
Still, we can accept that this is a major adaptation, and I'd even go so far as to admit I don't wish to argue that it's not evolution; the bacteria were able to digest something that they couldn't before. This is much more significant than a change in coloration or size because it would require several complicated mutations in the genetic makeup of the organism.
Now let's look at it from some different Creationist viewpoints.
The most hard-headed of religious zealot ignores anything that clashes with their beliefs. I don't think it takes much discussion to deduce what they will say about this research.
Another type of creationist is the strict constructionist who believes the Bible's version of the creation story is correct to the letter. This Creationist is unswayed by the research: making a bacteria out of bacteria has nothing to do with making a man out of an ape in their eyes. I imagine this group will be unimpressed and tell science, "Nice try, but come back when you can turn the vacuum of space into an organism in 7 days." It's important to these people that the proof of evolution starts from void and ends with a human, so this discovery has no effect on their beliefs.
Next, we have someone who believes the creation story as laid out in the Bible could be inaccurate other than a few points. God told man it took 7 days and he came from dirt because however many thousands of years ago the ancient Hebrew people wouldn't be able to comprehend matter/antimatter reactions or the evolution of unicellular organisms to multicellular organisms. These people won't be impressed by this research because their belief system can already include the origin of man as something other than dirt. These people would feel that disproving creationism invalidates the minor details of a few chapters of the Bible that generally get the large details correct.
Finally, we have people who simply subscribe to the philosophy of Jesus; to them the issue of creationism is irrelevant so it's obvious what an effect on their beliefs this will have.
Personally, I'm in the middle. One interpretation of the creation story decides that Adam and Eve were created as the start of God's people, the Jews. Other people existed and appeared somehow, evolution is as good a theory as any for how that happened. I'm not sure how much I buy that, but basically whether or not the creation story is exactly correct is probably one of the least important contributing factors to my faith. It'll be earth-shattering to me when you can prove that Jesus was wrong: being a dick to everyone you meet spreads peace and harmony at an exponential rate.
So far, in all of history and all of the universe, we only have significant evidence that a single planet has developed intelligent life. Some people feel this indicates that the odds are so poor that it is evidence of a divine influence. Personally I feel that's not the right approach and probability supports me: no matter how low the probability of an event is if you allow infinite trials you will have a successful event. That leads us to this experiment: in 20 years of free mutation, a single colony with significantly different traits occurred, and the researchers can have the mutation happen again when they start with a particular population. This is the exciting part: it shows the mutation isn't reliant upon something like a hundredth of a degree of temperature or something and possibly makes the odds better for a void -> mankind chain much better. I bet now instead of a number with 50 zeroes to 1 it's a number with 47 zeroes to 1!
So I guess what I'm trying to say is it's an exciting development, but the article's just not doing a good job conveying how this single event conclusively proves the millions of events that would be required to take a bunch of atoms floating around and end up with a man. It's definitely a great discovery, but I believe it's similar to a common problem I see budding programmers make on programming forums: They want a solution to problem X, and they know that problem Y is similar, but easy. So, they ask a question about solving Y, and several weeks later when they're crushed under the weight of lots of crappy code it comes out they were trying to do X, and a completely different solution was called for. These scientists seem focused on the problem of proving the ape -> man evolution, and they have proved a bacteria -> different bacteria evolution. Nice try, but call me back when the bacteria develops a nervous system or an eye and they can take any bacteria of a particular species and reliably produce the newer, more advanced one.
Note that I'm not saying that I don't think this is proof that large-scale evolution can happen; to say that would be to completely ignore the research. What I am stating is the crux of creationism lies with a belief in the supernatural: you can prove that animals, plants, etc. were created via natural processes, but you cannot prove that there is no divine being that set the processes in motion. My belief is we can prove how a deity did something without disproving the existence of the deity. Turning the supernatural into the supernatural is science's job, so if it takes motives such as, "We're going to show those creationists!" to get real research done then so be it.
Also, why are we experimenting on E. coli? Why can't we pick something that isn't harmful to humanity for our genetic mutation experiments? Don't these guys watch movies or read books?
*Note:* I wrote the vast majority of this post after misinterpreting the article to read as they had not been able to reproduce the mutation. After posting, I didn't feel right so I double-checked and saw that I was wrong. I came back and tried to take out the paragraphs that attacked this part; if I missed anything that seems to hinge upon the experiment's reproducibility please consider it retracted.
