Dengeki Online has a report in from the first of Takeshi Horniounchi's stage events for Rockman EXE Operate Shooting Star, giving a little insight to some details about the game. First is the confirmation of something we generally figured. As the game progresses, MegaMan will seemingly face Star Force MegaMan as a boss (likely connected to the ClockMan event). After beating Star Force MegaMan, he becomes an ally and a playable character during circumstances when Lan and MegaMan get into a pinch (however, it is not expressed if this can occur any time to the player's choosing, or if it's only story specific events). The report also mentions being able to use the cards connected to the Star Force series, and being able to summon Star Force MegaMan for the Program Advance "Double MegaMan." It is still unclear how Star Force's battle cards come into play and if they'll differ from Battle Chips.
Additionally, details are given about the minigame MegaMan Star Colosseum, which was thought up using Star Force 2's Colosseum game as a base. The game, which can be played wirelessly with friends, has players assuming a character such as MegaMan EXE, Star Force MegaMan or ProtoMan, and scrambling about trying to collect stars on the map. However, players can also attack other players to steal their stars, seemingly via a rock-paper-scissors item system. Grab items to change which attribute you have, and then attack the player whose attribute is weak to yours.
Portions of this game appear to take place on a wave road-like structure above the clouds. This could possibly imply the existance of such areas in the main gameplay as well (this is my own conjecture).
Check out Dengeki Online for more photos from the event.