I got the technet edition of Vista x64 with SP1 built in - so gave my PC a fresh install the other day
Reloaded grub afterwards so I can keep my dual boot ubuntu/vista setup
I am pleased to finally announce that after over a year of moving a file and watching it sit there for 10 minutes saying “Calculating time remaining” the file move/copy/delete bugs all now seem to be gone
I can copy a file from my housemates computer over the network now and instantly it starts transferring with a speed and time remaining - no delays
If I hit delete on a file its gone instantly.. heaven
However this is the only real difference I have noticed. The service pack was huge, has taken ages, but nothing really from an end user point of view has changed at all
The glass theme still has that HORRID 1 pixel cyan line on the bottom and right to tell you which window is active. BUT IVE CHANGED THE GLASS TO GREY!!
Someone needs to tell microsoft that blue isnt a universal colour that will look ok with all themes!
Also the lack of virtual desktops astounds me. I use ubuntu at work, and at home when coding purely because virtual desktops is a life saver. Code on one, website on another.
Its such a simple thing to do. Mac OSX has it, Ubuntu has it, Why cant microsoft write it in??
*sigh* back to ubuntu for me, keeping my stupidly expensive Vista install just for syncing my phone and ipod.. until someone writes a decent itunes replacement 
UPDATE: Oh yeah and now when I go into a directory with pictures in, the system doesnt hang for 10 minutes while it tries to generate thumbnails. Its still not instant like ubuntu but its a damn site quicker. The whole OS seems to be using a bit less memory as well