Yes, I think the surprise here is that they took so long to come up with it. Of course, the reason was the MD11 was in the way. Now that this aircraft is out of the way, it's only a matter of time before the 777F comes along and yes, I do agree, it would be very exciting. I can think of a lot of Asian airlines - Korean Air, SIA, Cathay, Malaysia, to name 4 - who would probably be interested. United seems to have set the ball rolling, as it wants a DC10F replacement, and has actually challenged Boeing to do this.
There's lots of discussions about new types, but I would see this as being pretty much a certainty . . .