Comparisons between Walcott and Henry are wildly unfair on the Frenchman, who despite being a preening ponce and a big game bottler was probably in the top five players in the world for quite a stretch, and, lest we forget, is Arsenal's all-time leading goalscorer. That is a status that Theo will certainly never threaten. He doesn't have the talent, he doesn't have that ego (the size of a small country)... he does have pace and finiishing ability but Henry in his pomp was about so much more than that.
But there is one other similarity. Thierry Henry spent a chunk of his early days pre-Arsenal marooned where Walcott is now: out on the wing. And because Walcott has only excelled in one area other than speed- his finishing- it makes sense that his future, if there is one for him at a top level club, is up front.
If that's the solution for his own development, though, it may only be another problem for Arsenal Football Club, who haven't played 4-4-2 since 08/09 and arguably no longer have the personnel to do it. Sure, you could pick two out of Bendtner, Walcott, Chamakh and (when available) Van Persie up top (and I haven't forgotten Carlos Vela, he just doesn't deserve to be even seen as an option), but if the midfield looks lightweight with three men, it would be even worse off with two. And the position behind a front three is the area in which Arsenal are best stocked- Fabregas, Nasri, Wilshere, Rosicky, Diaby (if he ever returns from injury hell), Ramsey (back soon apparently)...
If anything, this prospective dilemma underlines the lopsided nature of the current squad. Walcott is NEEDED in a wide position, despite being ill-suited to the role, because his pace offers a penetrative threat that is otherwise largely absent. Nasri and Arshavin don't really run beyond opposition defences when they don't have the ball. And Walcott, despite his pace, hasn't learned to do it consistently, which leaves Arsenal, on a bad day, looking one-dimensional and predictable.