Although only in the very early stages at this point...
The general plan is that all current appliances that include upstream software which also have new version available will have that upstream software updated. Software that has LTS (long term support) type versions available (e.g. Joomla) will use the most recent LTS version; other software will have the most recent stable version. In some cases if a major stable version has only just come out (e.g. v2.0.0); the most recent stable version of the previous version may be used instead (e.g. 1.9.20). That will be to maximise stability and will be decided on a case-by-case basis.
New appliances will not be added to the library unless they are complete and verified working. The TurnKey devs (including me) will not be building any new appliances for this release. The only possible exception may be the BigBlueButton appliance that I have almost finished (although most likely that will wait until v14.0). So if you want to see OpenERP and/or Oodo then you'll need to get them working! :)
I have no ETA for v13.1 at all at this point but it will be tracked on the TurnKey GitHub tracker wiki. I think that you should have probably at least a month although that's only a very rough guess. Even if you miss the v13.1 release; if it's very close to complete then hopefully v14.0 (based on Debian Jessie) won't be too far behind (v13.1) so you could get it in that release...
[update] As I just posted below we are going to skip v13.1 and skip straight to v14.0. This will mean that everything will bump to the latest stable version. Also I just noticed that Joomla no longer have the release schedule they used to and don't do an LTS version.
TKL v13.1 is on the way....
Although only in the very early stages at this point...
The general plan is that all current appliances that include upstream software which also have new version available will have that upstream software updated. Software that has LTS (long term support) type versions available (e.g. Joomla) will use the most recent LTS version; other software will have the most recent stable version. In some cases if a major stable version has only just come out (e.g. v2.0.0); the most recent stable version of the previous version may be used instead (e.g. 1.9.20). That will be to maximise stability and will be decided on a case-by-case basis.
New appliances will not be added to the library unless they are complete and verified working. The TurnKey devs (including me) will not be building any new appliances for this release. The only possible exception may be the BigBlueButton appliance that I have almost finished (although most likely that will wait until v14.0). So if you want to see OpenERP and/or Oodo then you'll need to get them working! :)
I have no ETA for v13.1 at all at this point but it will be tracked on the TurnKey GitHub tracker wiki. I think that you should have probably at least a month although that's only a very rough guess. Even if you miss the v13.1 release; if it's very close to complete then hopefully v14.0 (based on Debian Jessie) won't be too far behind (v13.1) so you could get it in that release...
[update] As I just posted below we are going to skip v13.1 and skip straight to v14.0. This will mean that everything will bump to the latest stable version. Also I just noticed that Joomla no longer have the release schedule they used to and don't do an LTS version.