There's some noise over at XDA forums about a bunch of people working on checking the Moto update servers and coming across what appear to be update patches that are intended for release soon. According to one poster (xda-developers - View Single Post - *Bootloader Unlock Research* Cheesecake Clarification), he flashed the update they discovered and soon found out it zaps the root exploit that we've all been using. Now he's got a brand new stock Bionic that is not yet rootable. o_O I think in order to stay rooted, I'm going to ignore the next OTA update until some developers have a go at it.
Additionally, does anyone know if there are any updates on unlocking the bootloader?