i think the main issue with games on vista that many overlook is that vista needs around 512mb ram to run while xp only needed a minimum of 64mb. unless you upgrade your ram to counter this, then you'll have less ram available for games etc causing them to run like crap or not at all due to your pc not having as much free memory.
looking at your sig, you only have 1gb of memory. if your using xp now and upgrade to vista you will most definatly notice a slowdown in games. i only had 1gb of ram when i upgraded to vista from xp and i went from being able to have medium-high settings in oblivion to having to set everything on low and i still had low fps.
as for the games in your list, i'll install hitman bloodmoney now and see if it works on my pc.