** Update 2: Looks like .1690 is available via WiFi now, so it's definitely an intended release. Not quite sure why my unit picked up the quincy stuff - maybe due to the fact it's prerelease hardware. Will be buying a new PlayBook in the morning so it's all good! **
* Update: OOOPS. With new icons for Server Urls, Bug Reporter and Quincy now installed on my PlayBook, I'm assuming this was an internal build that wasn't really meant for general consumer installation. I guess we can call this the LEAKED version of a PlayBook OS. Thanks RIM!!! *
Well this is interesting. While Adam and I have been hitting the Check for Updates button on the PlayBook constantly looking for a new software update, it turns out RIM has pushed one out via Desktop Manager. Plugging the PlayBook into the Desktop Manager via microUSB cable popped up the above prompt to upgrade to version 220.127.116.110, which I'm in the process of doing right now as I blog this.
So this confirms a couple of things to us about the BlackBerry PlayBook and the BlackBerry Tablet OS: