Nicolas,
I tried the new version of Hatari with IPF support on OS X this evening. As you said, Lethal Xcess isn't working. I only tried Blood Money this evening, but it worked great. I'll try some more games tomorrow.
For anyone else cares (Jerome?), I only had to copy the CAPSImage framework to my Frameworks directory (either system or user level) and copy the include files. I put them in /usr/local/include after creating that directory. When I ran Cmake, it immediately detected libcapsimage. Then, I had to change the Xcode project to add /usr/local/include to the Header Search Paths so Hatari didn't get a compile error because it couldn't find the header files.
I do miss the floppy light that I get with Hatari's FDC emulation. However, I also like the ability to run originally imaged games without the crack screens.
Thanks for adding IPF support. Hopefully, it will catch on and we'll see more ST disks in IPF format.
Bob C