From what I read, Vista is going to be pretty hard to "Pirate", pirated XP versions are already difficult to update to the point where Microsoft requires the installation of the GDI Tool, even with the Microsoft Windows Validation cracks floating around they still don't work when it comes to Microsoft validation your KEY, The only way to install IE7 and WMP11 on a Pirated Version of XP is to download a cracked version from a torrent site or IRC and risk the chance of packaged Viruses/Spyware that are ever growing in these distros. Vista is going to be the same way, except for they will include a requirement for KEY validations to obtain all quick fixes and service packs, good luck with those pirated versions of Vista, Better hope you aren't sharing a Key that Microsoft reveals as exploited.
Read: PC World's Article on the Uselessness of Pirated Vista.
Just one of the MANY sites exlcuding Microsoft's own that explains in more detail.

» Will you ever pay for Vista? ... Last Reply: 9 months ago by RightOn.
Alday:
Yea you are right to an extent. Microsoft does claim this every-time around, I do believe this time is going to be a little different. SOME of the cracked releases are great. Most don't work especially the WGA fixes, They still don't validate and MS is looking for valid Keys. Now if Vista's key doesn't validate, Vista will stop working all together, It will be interesting to see how the cracking community will find a way around this, I'm sure they will, but it is going to create a LOT of annoyances for users running Pirated versions of Vista. One thing about MS and their previous versions of Windows is it really takes them years to actually finalize it thanks to "Service Packs" These are going to be unobtainable through MS with Pirated versions of MS and the cracked versions might install, but Vista is developed to recognize them and stop working. It just seems like a cycle of annoyances not worth under the 200$ price tag for the ultimate version of Vista. Not to mention pirated MS apps like Office are developed to stop working under vista as well.