In addition to the normal Developer Blog post, the Japanese Super Street Fighter 4 Blog also made a post about the Japanese National Tournament and about the arcade version of Super Street Fighter 4 as well.
Andriasang states that the arcade release of Super Street Fighter 4 will come after the console versions, although no details on just how long it will lag behind.
What is interesting is that Andriasang states that Super SF4 assistant producer Shiozawa does not rule out the possibility of adjustments and adding more characters for the arcade version.
If this were the case, such changes would likely be added to the console versions via download.
Let me say this though just to be clear. Not ruling out the possibility of something does not make it an intention or an announcment. However, the fact that they have not closed the door immediately is worthy of note.
The "Nakky Blog" (names for Shiozawa's nickname) will become the "Saikyo Blog" (Japanese for "strongest" or "ultmate") after the game's April 28 release and will be written by Tomaoki Ayano, who will be working on the arcade version.