How about the Microsoft Office SharePoint Server 2007 Preview Site?  Complete with a demo and a product evaluation guide.  There is some marketing fluff (as expected) but hidden in there is some really cool information about new features. 🙂  I encourage you to jump in, I did and the water is nice and warm. 

http://www.microsoft.com/office/preview/servers/sharepointserver/highlights.mspx

And if you look around they have some other cool stuff previewing all of the Office stuff but we (me and my 2 dogs) only care about SharePoint. 🙂

Shane
SharePoint Help