Increasingly, Microsoft's deal for Activision Blizzard seems to be in peril. Reuters reported this morning that Microsoft is flying out to Brussels in Europe next week, to give a hearing to regulators to argue for its deal. Facing pushback from the EU, UK, and United States FTC could render the deal unworkable, although the UK CMA offered Microsoft the opportunity to spin off parts of the Activision business to reduce the power it would gain as a result of the deal. Whether or not Microsoft and Activision's shareholders would be willing to do that remains to be seen, but it…