I can't believe it. Seve pages of discussion on this one and no one mentioned Google Wave. Just look at this video:
http://wave.google.com/
Google got it so right. The web, and services like Google Wave, is the future. It's all about interoperability and free accessabilty. _And_ we have to differentiate here further. It's much more about the backend than about the frontend. Apple might write a nice client for Google Wave, but that doesn't matter anymore, because the money won't be spent on the frontend, but on the backend, as more and more companies (yes even Microsoft) have learned well from Apple how to design a good frontend. Or, to put it in other words, in a world with highly accessible backend infrastructure (read: web-based) you can chose from a variety of frontends. And, you won't need non-web-based frameworks to create appealing frontends either. It will not be easy to stand out in competition here.
Two last thoughts:
(i) Im really curious for Chrome OS with Google Docs/Spreadsheet together with Googel Wave. I guess this will really change the way we work today. Apple can only hope to „get on the wave“ (sorry for that :-D) asap.
(ii) I hope Apple has some competing products in the pipeline that can make a difference here. I would love to hear news concerning iwork.com. sproutcore is about to get to 1.0, and I guess they have spent lots of time and effort to get things right for iwork.com.