So it turns out that the hijacking of my blog's Google profile was the result of a reasonably well-documented, extremely clever Wordpress hack known as the Pharma Hack.
Several people sent me links and information about the hack...Thank you so much!...and my web designer (who's awesome by the way), got on the case and extirpated (I have so always wanted to use that word) the offending code from my Wordpress install:
Wordpress Pharma Hack extirpated!
In short, I was a bit behind on updating various bits and pieces of my Wordpress installation due to my extensive travel schedule, which probably left the door wide open for the low-life scum of the earth spammers to abduct my site.
If you run a Wordpress site and find yourself the victim of this hack, here are some useful links for more information: