When Microsoft calls a last-minute press conference to make a "major" announcement, there's only one sensible thing to do: pack your bags, fly to Los Angeles and get ready to hear what Ballmer & Co. have to say. With no hints whatsoever (not even a cheekily worded invitation!), we've nothing but speculation and rumors to guide us as we head into this news conference. Will we hear about Win8 tablets -- specifically, a Kindle Fire competitor running Windows RT? Or maybe today's news elaborates on
