The killer feature in Google Docs is the ability to simultaneously work on the same document with other people. The iWork cloud feature isn't as good and Google has always, in my opinion, led the pack on this useful feature. It seems to me that this feature will inevitably find its way into Pages and Word. In the meantime, Aditya Patadia and Hardik Pandya have already built a free version of an online text editor that pulls this off at LiveNote.org. If putting your data with Google creeps you out, this is a good solution for one-off text collaborations.