Klitschko
vs. > Klitschko
Briggs
. > Klitschko (undisputed champion)
Valuev
vs. > Valuev
Brewster
Maskaev
vs. > Hopkins
Hopkins
. > ? (retires)
Toney
vs. > Toney
Peter
This is the sequence that would be the best for the sport. If it unfolded this way, we would have two heavyweight fights bigger than anything the division has produced in several years. It would provide a fitting end to the careers of two future hall of famers, and we would be left with an undisputed and (mostly) unified title.
(Oh yeah. I'm assuming Maskaev gets by Okhello in his upcoming fight. And I would pick Toney over Hopkins as a heavyweight.)