Sven officially deconfirmed cross platform between the PC and console versions of the game over at Capcom Unity.
*"I do understand the desire for it, however in our experience, the usage of cross-platform play (as we’ve seen on LP Colonies a couple of years ago) is very low, even when in that particular case, the requirement for a Gold account on PC was removed for technical reasons by MS. *
For cross platform play to exist between GFWL and Xbox Live, as it stands today, the PC player must also be a Gold member.
Given the development effort, extra testing and logistical headaches trying to keep three SKUs (Steam PC version, non-Steam PC version and X360 version) all in lockstep for all future updates and not breaking anything along they way, it really isn’t worth it for the number of people that would take advantage of it."
http://www.capcom-unity.com/ask_capcom/go/thread/view/7371/28883961/SFxT_cross_platform_play_for_PC
While I realize this is probably “who cares?” news to the majority, it is pretty important to us PC fighting game enthusiasts.