Just found this thread:
http://forum.gtvhacker.com/sony-releases/topic658.html

Apparently I'm out of luck.

I suppose I could always pick up a new unit, root it, and return my old one with the complaint that it does not function as I envisioned...

Has it been confirmed that the recent OTA update blocked the exploit allowing root access? I dragged my feet and am wondering if I'm out of luck now.