Is MicrosoftLabs one of the GreatResearchLabs of all time, like ParcPlace or BellLabs?
Hard to say, MicrosoftLabs is fairly new. Unlike some of the other labs; MS labs seems more bottom-line focused.
On the other hand, much of the DotNet technology has come out of these labs; as has Microsoft's multimedia codecs (WindowsMediaNine? in particular). And then their's Palladium. :)
Whether or not these things will "contribute mightily" remains to be seen. Things that don't contribute to MS's bottom line, I imagine, won't escape into the public domain --the folks that run MS are far better businesspersons than the folks that used to run Xerox.
Part of what made XeroxParc such a technical success is what made it a commercial failure. If every computer maker/programmer who built a mouse, used Ethernet, used windows and pointers, etc., had to pay royalties to Xerox, these technologies may well have become technological footnotes.
At any rate, the collection of Ph. Ds that MS has amassed, including greats like CarHoare, is quite impressive. Whether or not MicrosoftLabs? will one day be uttered with the same reverence as BellLabs, I don't know.