OoB is getting an update this Thursday morning, and it appears that the new course (almost certainly the Oceania Resort course) will be available for DLC later that day. More details including price will likely be posted to the PS Blog on Tuesday. Be on the lookout for it!
We'll likely get that costume pack by next month- it was about a month in between the releases for the two in Japan. To be honest, i would rather see more courses any way. Now if they would just bring in a mini golf mode!