On the note of a Sega crossover, I'd be down. The issue with a Sega crossover is one that seems essential to most any crossover: choosing the best roster. Sega's history is so vast and and its situation a little unlike Capcom, I wonder how you'd do decent service to its history. Project X Zone was brought up: I was quite happy with the selections by and large because franchises I did not expect to see represented (RESONANCE OF FATE, VALKYRIA CHRONICLES) were in fact represented, and because of that game I came to be acquainted with SAKURA WARS. Like I said I come from a pretty narrow background of Sega fan, but I do recognize that some characters essential to how I identify "modern Sega" like Sonic, Kazuma, and Bayo aren't there. You include them and say NiGHTS and a few others I'd be happy, but obviously I should not choose a roster for this project or else Sega fans would threaten me. =P
The other issue is: What genre of game would we want? I don't know if fans would be down for another racer, at least not so soon. Sumo has reportedly done a great job with SaSRT and all that could change are about a half dozen roster additions at least, new tracks, and music. Some characters don't lend themselves well to this either (Bayonetta? Resonance of Fate gang?).
On the note of sexism, yeah it's subjective on some level. I think there's such a thing as fanservice content that is designed not to be aggressively patriarchal, fundamentally oppressive, or something of the sort, but the sad truth of it is it's influenced by the intent of the creator of a piece of art, so it's fuzzy of course. With the Alicia case, there are some pretty clear observational references that make it obvious that the art was intended for that kind of fanservice. It leaves a bad taste in my mouth, as was pointed out although she did wear a bikini for an extra scene in VC (and VC games have these types of scenes) her breasts are much different and there are varying levels of "offensiveness." We wouldn't want the only thing to remember Alicia by in game to be the beach scene.
Another example, think Morrigan from Darkstalkers: I think her design is authentic to a concept of a succubus without being fundamentally fanservice-y or symbolic of sexist attitudes. It can be interpreted that way in other media (i.e. fan art of her) though. Bayonetta...never played the game =P. I think the jiggling in PXZ is dumb and I wish it weren't there, but whatever.