If there is really enough demand and new PPC turboboards for the AGA Amigas would be produced, I'd consider this really a nice project, making lots of users happy and bplan earning a few bucks extra.
But personally I really wonder if it would be worth it to spend maybe 1000 Euro (100 for r&d, several hundreds for parts & production) for a pure expansion board that will be rendered useless once the 16 years old "main" board dies.
Thus I wonder if it wouldn't be better to let the development be based on one of the SOC designs bplan is working on for Genesi anyway, with a fat FPGA interconnected containing Dennis van Weeren's custom chip emulation for compatibility.
Of course this would require some software development as well to merge these two worlds, but in the year 2008, where the Minimig Amiga-reimplementation is available, AROS becoming more and more mature and with the Kickstart replacement bounty being at 2000 USD already, I wonder if the financial resources wouldn't be better spent on a complete mainboard and the beforementioned bounties to become finally independent of the old hardware and Amiga Inc.
And given the huge amount of years since Commodore became bankrupt, I also wonder if it would really matter to wait a few monthes more to mix something interesting out of bplan's current SOC designs, the Minimig and/or the Natami.