The teaser page shown on Pangya Japan is definitely Special Shuffle Course. It says "Next Update Pangya" on 2011/04/07. It should mean exactly as it says and nothing more. If they wanted to, they could implement other features along with this update like caddy upgrades and/or card pack volume 2. If that's the case, then it's nothing new compared to what Korea has already gotten two years ago. This update is scheduled to be released next week on Pangya Japan.
Since this update will be arriving next week, I cannot say this is a sneak peek look of the new season just yet. There are no reports of any beta testing, trailers, or anything new we haven't seen before. Now if they shown Wiz City in the background, then I would consider it differently. Wiz City would seem to be the new season 5 launch course and it would make sense.
If you like to learn more about how SSC could be like on Japan servers, you can check my Pangya KR Guide.