I would say no. A site that targets the iPhone browser is really a dumbed down iteration of a full website. The N900 has the advantage of being able to render the site(s) as a desktop would.

If anything, the idea that sites are forcing the N900 to mobile/iPhone sites is honestly upsetting since it can display darn near everything Firefox can - save Flash 10.x that is.

I don't think it'll help N900 owners.