Why it Doesn’t Matter if iCloud is Better
Federico Viticci posts up a nice roundup of developer complaints about iCloud and John Gruber of Daring Fireball says it's not as good as Dropbox for developers or users yet.
None of this matters because of this one fact: almost 70% of the 350M+ users of iDevices have access to iCloud, with some 100M+ using it already. Those are numbers Dropbox just can't match. iCloud may not be better for all use cases, but it does fill a very large need for simple sync.
Dropbox currently has some 50M users, nowhere near all of them on iOS.
Paul Haddad of Tapbots adds some very good points, namely that there is no need for another account or a third-party API and iCloud works in the background unhampered by Apple's restrictions.