I just figure this "baby" step allows Icom to use their existing DSP code, existing RS-BA1 remote software, etc, with minimal changes - without as much of a risk as a full featured transceiver.
Do you want this now, or the fancy model 2 years from now after all the new code is debugged? Hopefully they're working on the full size, full featured rig now.
The 7300 doesn't look too bad for a rig that is small enough to take field day portable, yet reasonable featured enough to use at home - at the TS-590SG price point. I hope it lives up to the initial hype.