Obviously I can't speak for the devs but generally appliances are constructed in one of 2 ways; either from Ubuntu (10.04) repos or from upstream tarball. If it's the former then an updated appliance with a newer version of RoR is unlikely (although not completely impossible), whereas if it is constructed using the latter then it is much more likely that the next revision will include an updated version from upstream.

Having said that, even if built from upstream tarball it will probably be a while before an offical updated appliance is released. I know for a fact that the devs have enough on their todo list to keep them busy for the next few years! So if you want a newer version of RoR and want to push an official release up the list then I suggest you have a play and try to update the appliance yourself, documenting carefully the steps taken. You may even wish to have a look at TKLPatch and release a patch that will automagically update the appliance. I'm sure others would appreciate this effort.

Good luck!

hi, as far as i know, turnkey rails uses Ruby Enterprise Edition, and according to their site, http://www.rubyenterpriseedition.com/,  100% compatible with the official Ruby interpreter, version 1.8.7 i dont know about 1.9.2 ....