This
article has a bit more info:
According to the terms of [Long's] contract, he's entitled to his regular salary of more than $700,000 for the final two years of his contract unless he gets a job somewhere else.
If he obtains other employment, his contract states, “You shall be entitled to no further compensation whatsoever from the date of that other employment.”
While it's always possible that the context could alter it somewhat the plain language there seems relatively straightforward, assuming of course that the reporter quoted the contract accurately.
And this makes it seem likely that he'll be obligated to stick around and work for SDSU, particularly sinced they've done it more than once in the past:
Long's firing is technically a “reassignment” for the remainder of his contract. Similarly, former Aztecs football coach Denny Stolz was reassigned to become golf coach after being fired after the 1988 season, with three years left on his contract. It's the school's way of still getting something for its money, at least in principle. Long's predecessor, Tom Craft, also technically was “reassigned” after his firing in 2005, with one season left on his deal. SDSU officials said he worked as a liaison between the school and former players and coaches.
Don Oberhelman, SDSU's senior associate athletic director, said Long's reassignment hasn't been determined.
Oberhelman said Long would be “incredibly valuable in a development role” if Long ended up sticking around.
That last bit sounds more than a little like they intend to sit him at a desk and make him raise the money they're going to have to pay him.

But it would also seem to preclude any action on Long's part that includes spending next year coaching in Manhattan since he'll be otherwise occupied in San Diego, at least if he wants to collect his $700k/year.
Here's hoping he gets a buyout.