I've just been through this process. I develop both PC and embedded software, and some of the tools are old. It took me nearly a week to get to the 90% point. This was for a transfer from an old 2.8GHz P4 to a 2GHz Core 2 Duo.
Basically the O/S itself is ok, and some things are better - network recovery from error is much better. But ... Easy Migration Wizard isn't Reinstall where possible Some XP drivers don't work Prolific USB to serial drivers cause the blue screen of death Finding out what to turn off is a real pain Turn off UAC for certain
Since Windows 7 uses the Vista code base, many of these problems will re-occur on an XP to w7 update. Good real serial port PCI boards are now seriously expensive. I'm told that the Keyspan USB serial adaptors work well, but I haven't tried mine yet.
On the PC development side, the DOS box isn't as good as it used to be - we still have to support 32-bit DOS apps with a DOS extender. The Vista DOS box doesn't seem to support full screen mode or graphics. For GUI apps, the RichEdit control doesn't work the same - Google for RichEd20.dll and APPCRASH.
Be prepared for pain, but you're going to have to do it sometime. We'll be keeping our XP install CDs for a while to come. And I'm never going to buy a Dell desktop again; back to generics.
Stephen