Note: On my drive home today I noticed my BB 503'd. Hitting reset brought it back to life. I've recently installed a couple of new apps, so I've removed them, but I'm thinking the most likely culprit is my addition of the Today theme.
If anyone else updates and uses the today theme, let me know if you have any issues. I've done this on all previous releases of 4.2 for the 8703e and had no issues. So if you see a 503, let me know, and I'll dig up another version of the COD and update my original post.
If you don't add the Today theme and see 503s, that would be nice to know too, since that then it would be an app/OS issue.