David Weiss, a Microsoft employee who works in the company's Macintosh software lab, gives a nice tour of the place on his blog. Sounds like it was a Mac museum of sorts until recently:
Up until a few months ago we had every significant hardware revision Apple has ever released since the dawn of time. We even had a section of the Lab we affectionately called the "Mac Nursery" where we kept all the older Macs going. We even had an old SE/30 and IIci and super expensive Mac II all connected via PhoneNet running Spectre, just for fun.
But the lab was running out of space -- although Weiss doesn't explain why -- and the team had to recycle a number of computers, including the original Macintosh, the Macintosh Classic and the Macintosh IIci. Maybe they could have put them on eBay, where a Mac Classic is selling for ... $31 at last check.