I think it's clear that Wenger has a long term game-plan. Sure, we may not win silver for a few years as he works on concrete foundations, but eventually this long-term strategy will put Arsenal on par with the other clubs for purchasing power. Indeed, he may even have to pay less should Arsenal's prestige help hold sway.
The man has done great things for the club and he is just as much a part of it as past names such as Seaman and Bergkamp. I'm behind the man 100% until things truly do become detrimental which evidently is not the case at the moment. The only sad thing about the club so far is the fact that Wenger doesn't have the CL to his name and it will be good day when that - which I do hope and believe will happen under Wenger providing he still has faith in the club - eventually happens.
We had a bad end to a mediocre season, it happens. Wenger is smart enough to learn from it and address what needs to be done. Only if things get progressively worse for say the next five years and Wenger becomes too stubborn to address them should fans be calling for his head. Current fans/supporters are only calling for his head through pain - just as you may say something horrible to a spouse whilst arguing - but they don't necessarily mean it.
The young team now really could be a power-house squad in five years which will be an absolutely fantastic base to launch Arsenal into long-term success. I predict big things from the likes of Fabregas, Gibbs, Nasri, and Bendtner.