The long awaited PC version of Super Street Fighter IV has been listed on ESRB. According to the list PC version of SSFIV will be coming out at some point in near future (we don't have any idea how far the listing is true).
Capcom's Captivate 2011 embargo ends tomorrow morning, it is expected that the listing will be confirm there. But we still advice you to take this as a rumor and wait for official announcement. You can check out the listing here.