Meh, the differences of game play worries me.
Street fighter has the punch or kick with different speed to damage ratios combined with undisproportionally powered super moves. Tekken on the other hand has a sofisticated assignment of keys to the respective extremeties. The special moves are not so overpowered, easier executable and blend better with the normal combat.
I don't know how well one can mix those different fighting styles.
The only thing which makes me hope for the best is the quality of the trailer which looks more serious and not so flashy like the capcom vs marvel games. If the developpers approached the game with at least the same seriousness, there might be a chance that the game will work.