I think the league will be a mixed bag next year relative to this year. United and Chelsea will both need to spend to stand still, whether they really will seems up in the air to me.
As for City, Mancini has been very conservative in his approach to this point and he's achieved a certain degree of success. Looks likely they'll win the FA Cup and make the top four - certainly the latter at least.
I wouldn't be at all surprised if they added two or more top attacking players in summer with the promise of CL football and unlimited wealth to hang out. The only question is whether Mancini will pull out more aggressive tactics.
Some talk about the FFP rules restraining them but we also have to wait and see on that.
One thing I do agree with is that Liverpool probably won't be top four material.