As much as people might dislike Vista, it's the operating system bundled with new machines and it's here to stay. It's been around 2 years since Vista was launched, whilst I can understand certain software developers might not offer support from the immediate release – it should be one of their high priorities. MMORPG developers seem to be among the worst for poor Vista compatability, along with other game developers.
Certain games decide that they need to run as Administrator from the moment the patcher starts up, even though the patcher might not need to download any file at all – therefore not needing to write any files to the Program Files directory. So the entire game runs under admin privileges, just incase the patcher might need to update files – Mythic Entertainment are guilty of this with Dark Age of Camelot.
Other games are still living in the old days where they still write any configuration files to the game directory for all players, instead of the relevant application data directory for the user. This is just extremely lazy and makes things awkward for users, instead of a clean split between game data and user data – everything is just lumped together in one directory. If I wanted to make a backup of my computer, it would be far easier to just backup my user profile which would contain any important data – however keeping this data along with the game itself makes it difficult. If I wanted to restore my machine from a backup, I'd lose any settings from the game.
There are other games which are complete failures, getting players to go with workarounds such as changing the permissions on the installation directory. After installing Lord of the Rings Online I didn't even get a shortcut to the game from my start menu.
If game developers could just put a bit of extra effort into game installation it would make things so much easier. I know the aim of these developers is probably just to get the game running on these platforms, but a fully functional game which works properly would save users so many headaches.