Akai better get that SynthStation49 out soon, as the imitators are beating them to the market. Samson's Carbon 49 is $89 and you can actually buy it now! The dock is more of a tray, or a slit, or just about the laziest possible way to pimp your keyboard for iPad compatibility. It can be directly powered by the iPad though, so they definitely got that part right.
Samson has some promo-videos on their site. They show it on the beaches of LA, and busking at a NYC Subway station, but all of the music in those promos come from the bundled Native Instruments Elements and not the iPad jamming we see in the video.
Instead, here's a more informative video of it at NAMM from UniqueSquared featuring DJ MadFlip, described by YouTube commentor THX11003 as, "This Asian dude is very fuckable." He is cute, but I think he needs to commit to the Mohawk and shave the sides, but at least he is, "Coming correct!"