[1] http://techcrunch.com/2007/03/14/microsoft-acquires-tellme/
[2] http://techcrunch.com/2007/04/06/google-launches-free-411-bu...
Furthermore, does the track record not show that Microsoft re-brands (assimilates) its acquisitions eventually? How do you (or the author of the linked post) know that the deployment of a Microsoft-branded 411 service was not part of this process?
Finally, everyone in the speech recognition industry knows that it requires a large sample set (utterances) to refine a speech recognition engine. If you are building one from scratch (Google), you will do anything and everything in your power to collect utterances. To think that Microsoft and everyone else in the industry did not recognize what Google was doing with GOOG-411 is preposterous.