To all complainers here: It's the same whining like XP to early days: "Ugh, Vista, soooo dooof and impractical" Yes it's true, Vista still has a few minor flaws but which are fixed by Microsoft regularly again. For performance: Yes, Vista eats more resources than XP (For me at rest about 500Mb of memory) If you're just using the office number, e-mail, Internet and Media Player User reaches 1GB RAM. But if you want to gamble on Vista, should call 2GB memory his own.
Conclusion: After a brief familiarization phase Vista is certainly better OS like XP. At the latest after the release of Service Pack 1 can safely buy Vista then each.