The life icons I can believe. Apple bought out a company that specializes in translating document formats, and etc, so it would be easy for them to write something into the finder that parses out what a Word document would look like, but I don't find this type of thing to be very practical for a few reasons though. When you think about it, when viewing these type of icons in Windows XP, most of the icons look alike, because they are so freakin small. Most people in Powerpoint use the exact same Themes over and over again so that wouldn't do much good either. It is a good idea, but when applied doesn't seem as practical. Now, if the Finder had the iPhoto resizing thing, where you can resize all the documents in the view, to get a clearer view of the previews, this would be useful though.
The Windows Vista glass interface would drive me up the wall. All the transparency hurts your eyes after extended use, especially since it's everywhere.
The most obvious thing that is likely going to happen is extending the way Spotlight works. Spotlight works great, but it feels like it's a small step towards something much much bigger.
The tabs in ichat was something that has been put in and pulled from numerous builds of OSX, so it is inevitable. The iPod Home Folder was a feature that was scrapped from builds of Panther, so I don't think it is going to happen. The harddrive in the ipod is too slow to boot from the home folder on it, and if it syncs with a home computers home folder, any of the transactions that would happen would severely slow down log in process. They would probably set it up so it's incremental, but even then though, it would add needless time to login for something that wouldn't make a huge difference.
Personally, I'd like to see the return of Voice Print where you can log in with your voice, and the ability to encrypt files again.