Is there going to a Marvel vs Capcom 4

Possibly, but unlikely to be any time soon. There was a ten year wait between the last two, and most of the team from the third game have left Capcom or are working on new projects elsewhere- Seth Killian in particular (important in both this and Tatsunoku vs. Capcom) is now working for Sony on Playstation All-Stars, and at EVO2K12, Capcom had a panel where they confirmed that they were moving on from Marvel for the moment, as the game is balanced and competitive enough that there is currently no need for a sequel.