He's actually really, really good in Brawl. He was spectacular in Melee if you used a lot of SHFFL'ing, (Short Hop, Free-Fall, (Press Down when at the pinnacle of your jump to fall faster to hit the ground faster. Also available in Brawl, thank goodness.) L-Cancel, (Cancels your landing animation, which isn't available in Brawl, but isn't necessary anymore.) but in Brawl, his attacks hit harder and more apparent-ly. Use his Bair (Back-Air) attack often, (The Helicopter kick.) against people often, followed by a grab, if you land behind them. Great combo.
Do be wary of the spin attack on the ground though. It can be dodged easily enough, and will leave you quite vulnerable. Rather, try to be in the air a lot, and use the boomerang from the air, aimed at your opponents, OR in the opposite angle from them, and land with an attack that'd toss them into its path.
Also, his arrows have been significantly buffed AND nerfed. For one, they move faster. This is a good thing and a bad thing, because although they have less time to dodge, it also is released faster, so it's harder to get it to go where you want them to go without already being in the line of fire.
Bombs are -VERY- useful in Brawl, as compared to the other games. I should mention that you should generally have a bomb in your hand when you have higher damage, because if it explodes in your hand while you're attempting to make the perilous journey back to the ledge, you get another chance to use your Up+B to recover again after you supposedly used it the first time. They also do knock people back quite a bit, when thrown at peoples' feet. Do spam the bomb and the boomerang, particularly in conjunction with one another. They ... ... affect each other. ;-D Heheh.