Canon could release disc printing in the USA if they were willing to pay the extortion fees to Epson, but they are not. Eventually they probably will.
Yes, this HP appears to be using an identical ink system, but probably not the same type head system. For disc printing, the main difference would be speed, if any. That said, the big problem with HP is the rather massive amount of corner-cutting they do on drivers and software and support. All other things being equal with this new printer, that alone is reason enough to choose the Canon. Also the HP does not have auto-duplex or the top-feeding paper feed option. (top feeding helps with things like envelopes and card stocks)