Will Microsoft+Skype have 68% desktop IM market share?

OPSWAT reported market share of installed Windows instant messenger apps for 2011Q2 (pdf). With Windows Live Messenger at 40.67% and Skype at 27.39%, that would put Microsoft?s post-acquisition share of the desktop side of the market north of 68%. Should this affect the EC?s merger approval? Does this market consolidation justify anti-trust restrictions? [...]