Poking around (it's a rather dull, empty office on that last day before the holidays so what else is a guy to do?) I found release notes for BB 8310 on the Vodaphone Germany site! They're a bit old, but these are the first I've ever seen. Get it while it's hot, I'm not entirely sure these are supposed to be available for download (internally the PDF is stamped "for RIM and Partner Use only").

Start here:
http://www.vodafone.de/hilfe-support...ry/112008.html

Click on the device (8310) which takes me here:
http://www.vodafone.de/hilfe-support...ry/116285.html

Top link there is to the Release notes! Taking you to an agreement page here:
http://www.vodafone.de/hilfe-support...85_119419.html

At the bottom right is a big red bar (don't worry if you can't read German, just click it) and you get the PDF file!

http://support.vodafone.de/docs/Rele..._4.2.2.173.pdf

Obligatory screenshot of the PDF file: