A couple of years ago, they were saying that the Natami would be shipped with AmigaOS 3, since then there have been several announcements on the forum about software which the publishers have given permission for it to be bundled with the Natami.
Recently there has been a lot of discussion about AROS which I did not read, so there might be a choice there.
The 68060 card is intended to be used for software development because of it's MMU.
The consumer board will use a softcore 68050 which is expected to be 2-3 times faster than a 66Mhz 68060, have 512MB ram as standard, and have a 1024 x 768 display without the need of a very expensive scan doubler.
As long as the Natami uses an FPGA there is the possibility of fixing any faults in the circuitry simply by reprogramming the FPGA, and when the design is finished you will be able to upgrade the Natami to use the planned superscalar 68070.
If you deduct the price of an 060 accelerator card which you would no longer need to buy for your Amiga, then the Natami will be very reasonably priced compared to any Amiga hardware.