The "problem" with USB audio on Windows 2000 as I understand it, is that Win2k doesn't allow low level hardware access to the USB controller. Likewise, it doesn't allow low level hardware access to ANYTHING. I've also heard complaints that since you can't change IRQ's in Win2k, you can't change the IRQ of the onboard USB controller. This is true, unless your BIOS supports the change, but can often be worked around via proper card placement.
I wouldn't necessarily call these problems, and Windows 2000 drivers exist for a lot of USB audio hardware. Yes, Windows 2000 driver support has been rather lacking, MOST of which is due to lazy manufacturers. Ok ok, lazy is a bad term....they concentrate driver support on the most used platforms, e.g. Win9x.
I have a Win2k DAW setup with m-audio hardware, and the advantages of Win2k FAR outweight the drawbacks. You could not pay me to go back to 9x, and you'd have a hard time convincing me to go back to NT4.
Windows XP is due out in October, but don't soil your britches over it just yet. If your manufacturer is having trouble with WDM support now, they'll probably still be having trouble in October. And no, Windows XP does not support windows 9x vxd device drivers. It does tout legacy application compatibility tools, but Windows 2000 shipped with similar tools (quite handy too I might add).
Personally I can't wait for XP, and will move to it as soon as I get all the necessary drivers. For typical hardware, see the current HCL:
http://www.microsoft.com/hcl/default.asp
Anyhow, about the Dell Laptop windows 2000 stuff. Microsoft is now selling licenses seperate from media. For instance, I was recently getting some quotes on Office XP, and I was quoted on 20 or so paper licenses, and ONE Office XP media pack (e.g. Installation CDROM's). It might be possible for you to buy the Windows 2000 media without buying a license, and it will probably cost about $20-30. But, since you've got a Dell, the Windows 2000 license that came with it might be proprietary. You know, you can always call Microsoft and ask (seriously)! I also think that you might be able to call Dell and purchase media. I order Systemax machines somewhat regularly, and they never come with Windows media (just a recovery disc), but I was informed that I could purchase the media from the Systemax reseller.
Slackmaster 2000