You can download it here. Although they are adding a few of the policies that have they should've included with XP SP1 or SP2, they still haven't totally replaced the IE Branding CSE (client-side extension). I've run into so many bugs with that thing that we just write custom ADMs to handle everything that it does. (that particular bug didn't get resolved until 5 months after it was reported to MS--so, no SP2 upgrades during that time if you were redirecting your App Data)
So, it appears that you will still have to either use a custom ADM or the always-buggy CSE to set something as simple as the Proxy Server.
But, it does look like they've added a lot of Vista-specific settings. Apparently they have gone from 1671 to 2450 available settings. I suppose I'll have to setup Vista in a domain environment to see how handy the new settings are. Also, it looks like they have things split up very nicely with the new ADMX format. I didn't count them all but it looks like there are a good 40-50 of them.
Also, as long as I am talking about Group Policy, I just ran across this GP Wiki. They have an "I Want To" page. I think I'll put a few things on there. ![Geeked [8-|]](/emoticons/emotion-15.gif)