First Class ended with Magneto and Xavier going their separate ways and the stage was thus set for inter-mutant warring in the future. It will be interesting to see where Vaughan and designated scriptwriter Simon Kinberg go with their follow up - one would imagine it will pick up fairly soon after the end of First Class and won’t skip forward to the modern day. After tackling the Cuban Missile Crisis and the sixties in First Class, perhaps the Seventies will be the era of choice for the follow up? Time will tell.
Keep eyes open for a confirmed release date though I can’t see it being before 2014 at the earliest as it stands.