I've been able to load Marcus' root servers. For pingpong, however, I don't know what to expect. Nothing interesting happened when I tried that, so I can't say if it worked.
pingpong does some ipc benchmarks, that's all.
You can see them on the console, if you compile the userland apps with:
$(SRCDIR)/user/configure --without-comport
If you forget this, the output goes to the serial port. It's a common gotcha... ;)
pingpong works pretty well.
/Niels