Hey, Street Fighter IV (like many other fighters, admittedly) has an infinite combo flaw! At around 0:27 in the clip above, you can see El Fuerte pound ceaselessly on Akuma, with the loop only broken when the guy controlling El Fuerte lets up after Akuma gets all dizzy. Should be fixed by the time a console version comes around, but until then, if you're playing at an arcade and a shifty kid with no friends picks El Fuerte, be on your toes.
UPDATE - Maybe not! Here's what Capcom have to say on the matter: "In that video El Fuerte does not chain together infinite FP cancels. He chains some together to dizzy the opponent and then repeats a similar combo to win in one round, but that hardly constitutes the use of the term 'infinite...Let's wait and see what the Japanese players say about the tiering before we hastily condemn anything".