Just thought it worth mentioning, been playing with my old 3GS this evening. Updated to iOS6, Jailbreak'd with Redsn0w 9.13 and installed Cydia via terminal. From what I can see all is working fine.

Will be testing some more over the weakend but if anyone wants me to test out anything I'll be happy to try it.

Assuming all goes well I'll be doing the iPhone 4 next, although it's only tethered so not ideal.