This was pointed out by one of our readers, DaFamX, and it made me do a double take and make sure it wasn't April fools yet. It appears this is legit though, according to IGN, Street Fighter 4 is coming to Apple's powerhouse mobile device, the iPhone!
It appears you will use the multi touch function on the left for movement, and there are 4 buttons on the right (Punch, Kick, Special, Super) for attacking. You can also link up two iPhone's via Bluetooth to battle it out with friends!
The IGN article mentions it is coming out in March, and will feature more than just Ryu and Ken, but a wide array of Street Fighter character new and old.
Source: IGN via DaFamX in iPW Comments