Personally, I don't think that there is any doubt that much of the movement (hype) around web startups (perhaps mashups is a better term?) will come to a halt soon enough. There's only so much attention to compete for and unless you are offering something unique or of great value, it will be difficult to sustain it for too long.
That's not to say that the web, as a platform, won't continue to be effective. It's just that there will be a thinning of non-essential apps and redundant services.
What do you think? What would a recession to to the web? Personally, I think that it might just promote some great innovation.