Although it doesn't appear to be in any jeopardy, the Google acquisition of Motorola Mobility has been put on "pause" for a moment by the European Union's Commission. The EU indicated that they simply wanted to gather more information. Here's a quote with more specifics,

Without going into detail, a Commission spokesperson only said that it was looking for "certain documents that are essential to its evaluation of the transaction," while Google says that the request is "routine."
Th official pause for the proceedings actually occurred on December 6th, but even before then, Motorola indicated that they anticipate the deal to go through sometime in 2012, implying that they expected this delay.

Source: TheVerge