Well DANG! So much to consider now! The E473 has some nice features with the S.Art. Lite, the 2 slots of DSP effects, and the morphing control they briefly mentioned. However, I am not crazy about the live-control knobs being so far away from the keyboard. For other things that I am hoping for, such as the ability to sustain both sides of a split keyboard with the pedal, the existence of portamento, and the key feel, we'll have to wait for the manual and to see it in person. I paused the video in several places, and I did not see a portamento button, but it could be a programmable function (like in the I500), or maybe some synth sounds could have it built in, like the Casio CTX700 and CTS400.
That vocal Casio looks freaky! I'm not sure what to think about it! So, yeah, I saw the video while it was still up, and that's exactly what it looks like -- lyrics are added from a smartphone and then synthesized into speech/singing. The song on the video had a very vocoder-like characteristic to it. It will be interesting to see if more natural human sounds are available. But my concern with this feature is that, it appears to play the lyrics in some sort of pre-programmed arrangement, and indeed, there were several times where it looked like the musician was playing one note, but several words were "sang", while at other times, each press of a key produced a new sung word. It would seem like if you made a minor mistake while playing that the words could get out of sync with your playing, but that's just speculation. And while many synths today do have more live-control knobs, that isn't always the case. Look at the original DX-7, which was pretty much completely menu-programmed with very limited live-control of altering the sound. But just like with the E473, we'll need to see what Casio does with the key feel, as they is a lot of room for improvement when compared with many of their recent models.