From reading some of the other messages sent today, I gather wine-pthreads requires nptl and the new (2.5.x/2.6.x) kernel?
Yes.
Is there any chance this is going to work with wine-kthread? Is the function pointer/wine_dlsym tricks some work around related to the fact that libjack is linked against pthread, but wine can't be?
No, just for dynamic loading of a potential present libjack.so.
For example, it is my understanding that wine-kthread provides pthread emulation -- is this method of loading libjack with wine_dlsym a way to get libjack to uses wine's pthread emulation instead of /lib/libpthread?
No.
Ciao, Marcus