vista actually isn't that bad. it's a lot more stable than xp but that may be because no one is trying to break it....yet.
licensing is never fun to deal with. unfortunately it's a necessary evil. i will say that as unpleasant as it is i have already seen the prices of vista and it's a lot less expensive than xp, even in retail stores. from what i have played around with it vista is basically a preconfigured ntfs system similar to red hat(linux) with a slightly different gui than standard windows. i am interested in seeing how the 64 bit architecture changes the way an o/s multitasks.
if you are looking to upgrade pc's for hosting check into server 2007. it seemed to have a lot fewer stability issues than 2003. plus you may be able to get it early. ok i'm done with my geek ranting.