He has never been a good 'footballing' footballer. I don't think he is now. But anyone who has watched Arsenal before Henry will know that pace is all you need to become a danger, and if you can finish on top of that, you will be a very effective player that can get a lot of goals. My namesake was never technically brilliant (although he could take on players much better than Walcott) but with Bergkamp feeding through the right balls, he would get into goalscoring positions. Walcott can do the same. Ljungberg's another -- he had less pace but worked harder on the defensive side of the game. The way Walcott intercepted for the 3rd goal should encourage him to do that more.
I don't know why people are so quick to put him down. Hansen, Gerrard, Waddle etc. especially. He has been given a raw deal by England. It wasn't his fault he was picked for the World Cup squad at 17 and he has never been controversial or said anything that'd annoy anyone. The 'hype' thing's a complete myth -- even when he was starting out, all anyone said was that he was ****in' quick. He made a big improvement in his second season but ever since he has been hit with injuries. If he doesn't become a very good player (at least in productivity) it'll be because of that IMO.
Wenger should be starting Theo over Arshavin now. Especially if Theo's going to track back as well as he did yesterday, he won't offer any less than Arshavin has been. Arshavin is capable of playing much better but his goals have dried up recently and without that he can be pointless. People can point to the number of appearances he has made but a LOT of them have been sub appearances; in games when we're chasing a goal and the opposition have 10 men behind the ball. It's more difficult to make an impact. He is not an 'impact sub' because he rarely makes an impact. When he starts, he plays a lot better. He has only scored once when brought on as a sub but he has 8 goals in 7 starts this season -- Wenger, being a fan of stats, has probably figured out he needs to be starting.