Scuttlebutt from the tubes says the rumored 5th Edition "Battle for Rynn's World" boxed set may contain the following plastic minis:
Marines
Captain with powerfist
Tactical Squad
Terminator Squad (possibly "just a couple" instead of a full squad)
Dreadnought (only 2 pieces!?!)
~Some or all of the models have been hinted at having Ultramarines iconography
Orks:
Warboss
Twenty Ork boyz (like the four man Ork boys set)
Twenty Grotz
Three Deff Koptas
Finally something in parity with the Battle for Skull Pass set