The big jumbo tweak that is Version 2013 for Street Fighter x Tekken has been detailed by Capcom as they release the changelog. Whilst some are just aesthetic, others are more nerd specific.
There’s an avalanche of character tweakings from the amount of damage done to frame reductions. This Version 2013 update is entirely free from Capcom. It’s a system change KO.
Frankly there are way too many alterations to be listed here, so if you want to peruse the changelog you’ll need to visit Capcom Unity’s blog for the full stat heavy details.
The Version 2013 update for Street Fighter x Tekken is expected to release by the end of 2012 for all platforms.