And is the deal between Marvel and Sony/Fox that detailed that adamantium is securely tied to X-Men? Seems like that metal would be "public domain" as far as the various Marvel movie characters are concerned, don't see why it'd only be latched to X-Men and thus only Fox.(?)
Essentially, if it's mentioned or seen in a FOX-produced Marvel film, FOX holds the rights to it from there on out (which is one of the reasons there were so many
fucking worthless and pointless cameos in The Last Stand
and X-Men Origins
). Marvel has to stay away from basically anything even remotely mutant-related, and adamantium is pretty closely tied to Wolverine.