Julia Lerman reminds me of trying to explain XML encryption and digital signatures through a translator to a Japanese audience last year. I got mixed up at some point and was having a tough time getting back on track, with the added worry of how it was all coming across in translation.
The sad part is that the general audience for WSE and Web Services development has to know about these details right now. My opinion is that the WS-* specifications should be just as hidden as the TCP/IP stack to most developers. If you need to know, you can get at the details, but most just need to be building business services - not worrying about how a public/private key encryption scheme work. Hopefully, we'll soon have a toolkit where developers can worry about business value and not plumbing.
In the meantime, we have courageous speakers like Julia and Michele to explain it to the masses. There's also John Bristowe's WSE FAQ.