This would never happen in the US; That is for sure.
I'd like to see it.
I say the following fighters:
(from all orgs)
HW: Fedor, Alexansder(fedor's bro), Couture, CroCop
LHW: Shogun, Rampage, Liddel, Tito
MW: Anderson Silva, Dan Henderson, Matt Lindland, Phil Baroni(everything needs a hotshot and some laughs)
WW: GSP, Hughes, Kosckek, Serra
LW: Sherk, Gomi, Stevenson,
That'd take about a billion hours to do, but yeah... just have it in several parts. I'd pay actually dollars to watch that.