I'm sure Marvel had already discussed what Phase Two would contain in terms of films and stories years before, and would have mapped out funding for them regardless of how much Avengers would rake in at the box office. If Thor or Captain America were relative failures and but Phase Two went forward anyway, there may have been room for a Hulk movie with Ruffalo based on his reception in Avengers. As it stands, IMO Marvel have enough hits on their hands to press forward with plans, funding and contracts as envisioned.
Also, Greenlight! a Hulk movie! Get it?!