Sega of Japan is apparently bringing the party, registering a trademark and logo for Let's Party. It could represent the latest in a line of software from developer Prope, responsible for Wii games Let's Tap and Let's Catch.
Sega's trademark with the U.S. Patent and Trademark Office doesn't tell us much, other than Let's Party is being protected against "video game software; computer game programs" and "providing on-line games; providing information on on-line games." Yes, this is a video game and it may have some online component.
Since Let's Catch was a WiiWare title, that "on-line games" mention may simply refer to its distribution method.
The only thing that leads us to believe this isn't an entry in the already existing "Let's" series is the logo. It's out of line with the established design, for whatever that's worth.
To the best of our knowledge, Prope—a small studio headed by former Sonic Team lead Yuji Naka—hasn't gone on record about its follow up to Let's Tap. If this is it, Sega and Prope look to have found a groove.
Let's Party [USPTO]