To everyone that took part in the Windows Vista beta test (as far as I know, about 20,000), only those that submitted at least 1 bug report will be offered a complimentary copy of Windows Vista Business or Ultimate.
Microsoft sent out a mail to those testers just a few minutes ago which specified that it is being offered as a download only. No media will be mailed, and only currently active, invited members of the Windows Vista technical beta program who filed at least one bug are receiving this offer.
Kudos to Microsoft! I'm sure I'm not alone in saying that they have really shown their appreciation towards the people that actually took the time to submit the bugs that were eventually worked out of the final code, some bugs that were submitted by beta testers didn't make the final, among those is the now infamous explorer folder selection bug* where the folder remains selected in the tree view, deleting a file or folder in the folder view (right pane) actually deletes the selection in the tree menu!
Microsoft had already announced that this was too late to be included in the signed off code and it will be fixed with a patch update.
*Workaround = Click on an empty area in the right pane first before deleting anything.
Link: Did you submit a bug? @ Connect