I think there's definately interest. Despite the "NG" amiga platforms (mos/os4/aros) being more vocal on the bigger amiga forum sites I suspect that the classic amigas still have the biggest user base when you combine users of "real" 68k amigas, fpga based machines and software emulation. I guess one of the problems with developing new custom chipset based games is both the time and effort required to make something that'll interest people enough to look at it (after all there's thousands of amiga games already so a game needs to look on par to get more than a 2nd glance usually), and the fact that the amiga isnt an easy machine to get good results with for some game styles, and both remaining good amiga coders and good documentation/examples for those trying to get to grips with the hardware arent easy to find.
The new games for the 8bit machines, while still cool, just dont take the same sort of time and effort (assuming a person wants to make something look decent).
As for open source ports, they do often make thier way to 68k amigas too, but unfortunately are usually only suitable for emulation due to both general inefficiency of the foreign apis and toolkits (as well as far from optimal compilers) theyre typically only fast enough on emulators. WOS/PUP ports seem to seldom happen nowadays unfortunately though.
Just my 2 cents
