It's basically a Korg Oasys with a couple of extra instruments included (a disk streaming acoustic piano and a modelled electric piano), a weight reduction(!) and a reduced price tag, which seems to have upset some Oasys owners!
Interesting how the Oasys is not mentioned through the launch! I have an Oasys 88 and think it's the best sounding synth I have ever owned but it's very heavy and difficult to transport. The 61 key Kronos is much lighter so should be good for concerts.
As a reply to your question, if the Kronos has the same D/A converters as the Oasys then I definitely take a fancy to this as the Oasys sound is superb and the flexibility of all the synth model options will keep anyone busy for a very long time.