From this Gamespot article:

Frank Pape: We’ve got something better than that. We’re announcing today a fantastic partnership with Cryptic Studios and Marvel to create the Marvel MMO. It will be on Xbox 360 and on Windows, and will feature cross-platform seamless simultaneous play, which we believe is unprecedented.

Gamespot: So it’ll be the same people on the PC as on the 360?

FP: Absolutely, playing at the same time, which we think is tremendous–a unique and compelling feature for folks to play the game…We think that it transcends boundaries across the two platforms.

Playing on two platforms at the same time, in the same server space. If there is PVP, it will be interesting to see if they can pull off something that feels fair no matter which control scheme you happen to be using.

GS: Now I presume, the game is going to let you create your own heroes. My question is, how are the characters from the Marvel universe going to interact with those newly created characters?

Jack Emmert: Don’t presume anything right now. We are dedicated to creating the ultimate Marvel experience online and we’ll do whatever it takes to fulfill that. Whether you can play as a character or create your own–right now, we’re not announcing anything.

Translation: yeah, they’re still figuring out the BatmanSpiderman problem.

Oh, and here’s my personal pet peeve regarding microtransactions:

Jack Emmert: Well, we can’t talk specifically about anything but certainly we’re excited at all the opportunities that the Microsoft Marketplace offers to us.

Ames Kirshen: [W]hen we first started sitting down with Microsoft in Hamburg two years ago, they really kind of let us in behind the curtain and showed us what they’re going to be doing with 360, with Live and Marketplace. That was a big reason why Marvel felt comfortable going first-party with the MMO and I think, given where they are with the platform now, we’re all pretty pleased that we made that decision.

Frank Pape: Adding to what Ames said, for us we have the resources to bring to bear on it, Live is obviously the dominant online console platform today. And Windows Live is going to have seamless integration with Xbox Live. Obviously we’ve seen it and lived it over here and Marketplace obviously offers tremendous opportunity.

Saying “the Marketplace obviously offers tremendous opportunity” reads to most gamers as “it offers tremendous opportunity to us, as we fleece our customers for everything they’re worth. It takes so little effort to explain how the Marketplace will offer benefit to the customers instead of to the developers.