The reason why business loves BB and think of the iphone as a toy is simply because of the BES.
http://en.wikipedia.org/wiki/BlackBe...erprise_Server
We have over 300 BlackBerry's at my work and managing them individually (like you would have to with the iphone) would be a disaster. Like I said in the BB thread, pushing security policies or applications to 300 devices with the BES is a few simple clicks. This simply does not exist for the iphone - although I have read Apple is working on some sort of central management for them.
If you are not in a corporate environment, however, then yeah - there isn't much difference between how they handle email. In said environment though, sorry, it isn't even close right now.
I love the iphone, but if you need to do boring work stuff with it (corporate email, viewing and editing of documents, IM to groups of people, etc.) then BlackBerry is still king.