[quote=@t2wave]
I didn't mean making amalgamation characters. Just that the worlds would be a mashup.
[/quote]

Honestly seems like the best idea in my opinion, really.

[quote=@clanjos]
On topic, just how much of Marvel and DC's canon would we be allowed to use?
[/quote]

This is a good question though, really.  Bare in mind that the Marvel universe has canonically contained Godzilla, Combattler V (and other Japanese super robots) and has Transformers and GI Joe in a weird state of quasi-canon.  Also that Conan the Barbarian is technically canon to it. XD

Basically what I'm saying is that there's potentially a lot of strange, cool stuff to play with.