1. Windows 7 is not 'needed' in order to run Trainz. Trainz was designed for XP.
2. Windows 7 will not be released until October 22.
3. I have been using Windows 7 Ultimate RC1 64-bit for about three weeks now and TRS2004 runs superbly. I cannot comment on other versions of 7. I own 2006 & 2009 but haven't got around to installing them yet.
Darrel