Street Fighter X Tekken will be getting a free balance update at the end of the year, just like SSIV AE did last year. The update is due in December, and Capcom has detailed some of the changes coming to SFxT "v2013."
A post on the Capcom Unity blog details the changes, all of which seem to be buffs in the form of factors like increased distance, new chaining options, and increased damage. The post does say that more details are to come, though, so we would expect a few moves to be nerfed as well.
The blog also notes that new swap costumes will be available for 50% off for two weeks, and notes that the Vita version already has the PS3's alternate costumes. It's due on October 23, and the blog shared a new "Features" trailer for it.