What about Caiera the Oldstrong who was the Hulk's love interest in that series?
what about the WarBound characters he teamed up with?
I wonder will any of them be dealt with at all, since this is ultimately a Thor story.
"With Great Power Comes Great Responsibility"
Stan Lee, 1962
Never read the comics, but I enjoyed the PLANET HULK animated movie. I didn't really care for any of the supporting characters. They're not bad, I just wouldn't mind if they never made it into the MCU.
This is still a THOR film, so we probably don't want too much PLANET HULK to spill into it. At least adding Caiera could be interesting, though if they are ever able to loosely adapt WORLD WAR HULK, I would like them to do it in a way it's also a sequel to THE INCREDIBLE HULK. Bring back General Ross, maybe as Red Hulk, Betty, and hopefully Stern will have mutated into The Leader. Maybe Abomination.
http://www.freewebs.com/demonictoys/
There's a thread saying that basically Ragnarok is a planet and the plot is vaguely similar to Planet Hulk. Assuming it's true, we could see a few characters.
What's missing in movies is same as in society: a good sense of work ethic and living up to ideals.