The big problems with Windows have been malware — maybe 7 has finally fixed it and if so good for them — and DRM.
Good luck with that posit.
According to today's security alerts, Windows 7 has bugs in COM, cryptoAPI, LSASS, and of course in IE. Some other vulnerabilities in the announcement don't affect windows 7, but there's enough that do to prove they haven't learned how to write bug-free software yet.