It looks like SMAP is going to make sure that they aren't leaving their Japanese fans out in the cold as not only will they be doing the concert at the Shanghai World Expo they are also going to do a dome tour in Japan starting on July 31st. They are slated to perform in 8 domes around Japan which if they all sell out, which they should do easily, will break the 10 million mark for audience attendance for all their concerts.
Also they announced that for this tour they will be releasing a new album titled it We are SMAP! and it will go on sale sometime in July.
Nikkan Sports article. (Japanese)
So it looks like July could be a big release month for Johnny's if Hey! Say! JUMP's upcoming album is released in the same month. Also this far into May it seems to be getting too late to announce anything for a June release so I think July is looking to be the month to look forward to for Johnny's releases.