Maybe I'm alone, but I like those kinds of reviews. For big name games, I've already read a lot about the games, so I don't need someone telling me something I already know. I like to hear about nuances in gameplay, surprises, annoyances, what worked and what didn't, etc. - things you don't read everywhere.
So far, Mario Kart Wii sounds like a step down from Double Dash in most respects, save for the online mode. The sheer fact that you cannot play Grand Prix in co-op to unlock things seriously pisses me off. I'm pretty good at Mario Kart, but the computer controlled players are often so brutal, that I need an extra player to help take home the gold. And from what I've heard, 150cc is even more brutal in this game than ever before. Oh yeah, and since it's Wifi enabled, I'm sure you won't be able to back up your save games either....sigh
Battle Mode was the most fun in the Super NES version, and the N64 had some great arenas, but since then there's been so many bad arenas. I liked Double Dash's Shine Sprite and Bob-omb battle modes, but Luigi's Mansion and the Pipe Dream levels were the only decent stages in that game