A few weeks back we starting seeing something messaging related that would be coming to CyanogenMod. This was for those using Google Voice and was originally sporting the codename of Babel (just like Hangouts). Anyway, in a bit of a status update, Koushik Dutta has announced the new name and perhaps more important -- that this project has been merged with the nightlies.
The app is called Voice Plus and basically means the user will be able to route all incoming Google Voice text messages to the standard Android messaging app. Or for that matter, any messaging app that you can set as your default on Android. Anyway, as mentioned this has been merged into the nightly builds, however we have yet to get any idea when it will arrive in a stable build.
With that in mind, the Voice Plus setup is simple and to the point. You will be required to keep the default Google Voice app installed on your handset, however once the Voice Plus setup has been activated all messages will be routed accordingly. The activation process is basically just launching the Voice Plus app at which time you will be able to pick the account you want to use.
From that point all incoming text messages will route to the default messaging app on your handset. The Voice Plus app is also where you will go if you want to reverse the process. That being the case, it would just be a matter of re-launching the app and choosing the disable option.
Sadly though, while this solves the issue of having to use the less-than-ideal Google Voice app for messaging it unfortunately doesn't help the lack of MMS support.
SOURCE: Google+ CyanogenMod