I'm in Redmond this week, being educated on SharePoint 2007. SharePoint has a lot of potential: it's bewilderingly complicated in terms of setup and configuration, but it also has some amazing capabilities.

I spent a few years working on Portal back-ends from, oh, about 1999 to 2003 and it's interesting to see some of the ideas we thought about (but couldn't manage to bring to fruition) appearing in SharePoint. And done quite nicely. I predict that SharePoint will do quite well as a web front end, especially once people pick up on the power of features like the Business Data Catalogue, which effectively lets you create some (simple, at this point) level of composite application from various back-ends.

SharePoint 2007, BTW, works quite nicely in Safari on my PowerBook (which I have with me - and I'm not the only one). It doesn't have the tight Office integration that you'd have on XP, but the functionality is all there otherwise.