no 16 bit emulation (can't play duke nukum)
Very few drivers for 64 bit (printer wouldn't work, tv tuner wouldn't work, a number of other things which were small)
Extremely limited choice for free antivirus (all I could find was avast)
Now of course, you have much more support for the drivers and the antivirus, but I still think I can't play duke nukum. We'll see when I install 7 (dosbox should work though).
Much of the world is still using windows 2000, so we've got a long way to go before we can abandon legacy. However, it's important that we move forward when we can. Apple got it right in this way, but at the cost of severely limiting the number of programs available. My uncle is an optometrist who has some equipment whose software only runs on windows 2000, and the company who made it is either dead or stopped supporting it. He's not rich enough to buy a newer version either (especially not when the old one works just fine).
"Parliamentary inquiry, Mr. Chairman - do we have to call the Gentleman a gentleman if he's not one?"