In this interview, Donald Trump implies he is happy with the Republican presidential candidates, and that he has no interest in running as an independent. Thanks to Politico for the link.
From that source:
GRETCHEN CARLSON: You have said that if you did not love the Republican field, that you would still consider to get into this race as an independent.
Now that you know that the field is pretty much what it is, what do you think?
TRUMP: Well, I think the field is starting to look pretty interesting and pretty good. And, look, the key is that Obama be beaten.

He’ll endorse Romney, I predict.
Trump “campaign” was always a publicity stunt. He never intended to run.