We've only seen two levels from the upcoming Kid Icarus Uprising, and that was all the way back in January. The demo we saw had two parts. Each level started off as a flying game, where you control Pit with the Circle Pad and aim with the touch screen. You shoot down all the evil monsters and demons in sight as you fly over oceans, through canyons, and around cities. It's one of the best looking 3DS games we've seen so far.
There are also ground combat levels where Pit fights huge scary bosses. The controls are largely the same, giving the game an odd shooter feel even when you're in combat. Plotwise we've seen Medusa, the game's main antagonist (and final boss from the original Kid Icarus). She's back, and she's pissed.
Kid Icarus will definitely be shown at the Nintendo press conference, but we think it's going to take a very back seat among all the Project Café announcements.
Nintendo's demos for handhelds have generally been pretty light, so we're likely looking at two levels again, and it's possible one of them will just be an updated version of one we played. As one of the 3DS graphic powerhouse games, we're excited to see how it looks now, months later. Nintendo has yet to confirm if Kid Icarus Uprising will feature multiplayer. Expect news on that, and if yes, likely a multiplayer level for us to play.