I figure this will be the first of several Internet related updates, but it came as a nice surprise today when I read about it. I downloaded the update tonight and it just adds YouTube to your list of options on the main menu, and is really easy to use. All videos open up to full screen, which is neat to see on a large TV even if the video quality isn't great. You can browse the same ways you can on the website (newest, rating, this week, today, etc), and when a video finishes you are taken to a related video page.
Anyway, just a nice little add-on that I see getting a decent amount of use at my house.
Now that I've had time to sit down and deal with the various parts (upgraded the CD-RW to a DVD-RW, added a 60 GB hard drive), I have what could be a very functional PowerMac G4. It appears to be the AGP graphics version, no gigabit Ethernet.