This is now live. It seems to be a DAC with some additional playback capability owing to its internal storage. The price starts at $400. They have device-specific models, which will only work with specific phones. So, there are different SKUs depending on the device.
Now, they have a table to help compare features with existing products, which lists a Mophie battery (huh?), a Pono player (double huh?), and an AK240. You can find it here:
What they should compare to, in my opinion: V-MODA Vamp VERZA, CEntrance HiFi-M8, and a Fiio E18 w/ a Lightning-to-USB adapter if needed. I built my own table, and it looks like the E18 is a worthy competitor spec-wise to the promised Geek Wave, if you are willing to give up (a) DSD, (b) 192kHz and 384kHz sampling rates and 32-bit sample depths, and (c) the built-in 256GB memory. The E18 can be had now for well below $200, even if one adds in the Apple adapter (but charging capability is lost for iOS).
I'm also pretty confident based on how other storage products work with smartphones that the memory on the Geek Wave will be separately managed. I doubt that it will make your phone's memory automatically larger; instead, it will give you an additional space to put music in, perhaps with a separate app to access it (this is how other mobile storage solutions work -- Seagate is a good example). I could see this being really cool if they somehow put the music decoding in the Geek Wave and it could run "headless". Start a playlist with an app, then turn off the phone and listen for hours. (This is my wishful thinking.)
I also find it fascinating that the campaign acknowledges the cabling issue -- "help us make the connection better."