I can't see this game flopping, as long as the netcode is better then Marvel. It's got appeal to combo freaks, and anime fans. The only concern will be balance, but I don't think even super-K' will be THAT bad, if other chars got buffed up, and SNK has time for some last-minute balance tweaks also (probably about six weeks)
If K' is really bad, I just hope EVO folks bitch at SNK to fix him (is SNK there or just the build?)
On the unannounced chard being DLC- I'm actually cool with that, but on one condition. It's not like creating 2D chars at this level of detail is easy. This isn't 10-minute SSFIV character creator here.
Where you're pumping out DLC, you put patches into the game to rebalance to go with the DLC.