In my prior WinXP, I didn't do very much with WMP (frankly didn't listen to much music on the PC).
On the work machine (a Vista laptop) I've enjoyed the Whitecap visualizations - of course in WMP 12 it was difficult to figure out how to get the same stuff done. Seems like the preferred method of setting it up has to do with 'Now Playing' and then right-clicking toward the top. No menus, and getting the visualization to show took some effort but I got it working.
And then figuring out how to get the playlist to show with the visualization - right-click again. Seems like there's a lot of stuff on the right-click menu (i.e. equalization, show playlist) that I use a lot, someone at Microsoft figured that if you hide stuff people can play a game of hide-and-seek. Sheesh!
FWIW I love Windows 7 - so much better than XP at home (my Dell PC would not upgrade to Vista no matter how hard I tried) and so much faster than the work machine running Vista.