I took advantage of the XP downgrade on my new pc, (Dell Vostro 410) and it was actually less money than for Vista preinstalled.
Additionally, I received 2 OS disks, each containing the full OS setup, one was XP, the other was Vista Business. (no restore partition or restore CD crap)
The XP disk is keyless, meaning it installs without needing to enter a key. Vista would require the key that is printed on my license.
And the PC didn't come with any crapware bundle preinstalled.
Gotta love Dell Small Business.