I think this is, more or less, a last stand thank you reign. I mean, Mick went out on his WWE pretty poorly - the last image of him on WWE television is getting put through a table by Edge, and I guess this is TNA's way of thanking Foley for everything. It's a nice thought, and I think Foley has certainly done enough for the business to deserve this sort of reign.
That said, of course, Mick Foley cannot and hopefully will not hold this belt a long time. I'm all for giving Mick one last stand - a month or so of feuding like he just did with Sting, a few Impact hardcore matches, and at the next PPV (or on an Impact soon after), have him drop the title to...well, the fields open. Hell, even earlier potentially. He could drop this Thursday, like Sting did post BFG 2007. Or on an Impact prior to Sacrifice. In any case, there's no way Foley makes it to Slammiversary as champion - I can't imagine him in a ladder match. Even though he did manage to climb the cage, a ladder match is much rougher than that. Foley's longest world title reign to date is 26 days, and that's probably just as good a length for this time around.
The man to whom he drops, well, the field's open. If Lashley winds up heel, he's a great choice. Angle could definitely do it and make a great match in the process. If Jarrett turns heel, he could as well. Or, Foley could, being Executive Shareholder, book the title shot to one of the TNA Frontline - Styles, maybe - it's pretty clear that Styles is getting something big at Sacrifice. I could see any four of them beating Foley for the title.
All in all, this won't be a long reign. I could see Foley dropping to a face (Styles) and then going back to the Executive Shareholder role. If he drops to a heel, it might be under some stipulation that if he loses, he must retire from wrestling. Such and such. I think he'll do well as a transitional champion, and I'm glad that he gets to go out with a bang.
Or, perhaps more appropriately, a "Bang Bang".