Back in March, 4 arcade games were released on the same day. That is equal to a month of 1-game weeks. It was also released on the LAST Wednesday of the month. So I'm guessing that every last Wednesday of a month, both the US and EU will get 4 arcade games, and they'll be the same games for both US and EU as well. I could be wrong, but that's my guess.

I would assume the Wednesday was only because it was timed to coincide with the GDC presentation. However, I would love to believe your theory since it would mean an extra update day and more games per month. It still doesn't explain the conspicuous absence of C64 updates in the US since the console's launch on the VC. Nintendo just doesn't make sense.

I'm sure we're gonna get some more C64 games in the future. Right now I'm a little concerned about the Neo Geo though, it's been a while since it was updated (December I think).

That would be great if true; even better if it wasn't all catch-up with Japan!

I agree that it seems unlikely, but Nintendo have the VC Arcade releases in the important news on the home page of the Wii Shop still, so it could very well have a different schedule to normal games - especially since they are titled VC Arcade, rather than just VC.