The question is what shape will it really be in, and will it be worth it. A lot of good has been said about Windows 7 since its beta came out. Requirements of systems are known also at this point, including needed a minimum of 1 GB or ram 2GB if you are going to use XPM.
Speaking of XPM you do need to make sure that your processor supports the hardware virtualization for it. Both AMD and Intel have software that will check your processor and let you know if it can support XPM.
As it is, one of the online DJs I know did his show from a Windows 7 machine last night, and running the software for DJing in XPM mode worked great for him, which does give some hope that Microsoft got it right.