Seems to have been coming for a while (<a href="http://techcrunch.com/2011/12/05/gowalla-acqhire/" rel="nofollow">http://techcrunch.com/2011/12/05/gowalla-acqhire/</a>), but I think they just pulled the trigger judging by this tweet <a href="https://twitter.com/maxvoltar/status/178658732950040576" rel="nofollow">https://twitter.com/maxvoltar/status/178658732950040576</a>.