This statement sounds like you have no IT support department to fall back on when stuff doesn't start working.
I work for a huge firm and we are just now migrating to exchange 2007 and by 4th quarter 2010 or 1st of 2011 we will be moving to Windows 7. With that said, we have had about 2 or more years of testing via MSDN on TEST and QUAL boxes with the 5000 or so applications we use and support to ensure compatibility or get justification to upgrade to a compatible version before the roll-out.
You don't want to go out and arbitrarily upgrade your XP work desktop to Windows 7 without ensuring compatibility and stability unless you would like a small nightmare.