Researching, I see lots of talk about the Say command and TTS (especially the loss of Google’s).
Vera/MiOS has a Sonos plugin that allows for use of the Say command and is working with other TTS engines like Mary and Microsoft. I can’t help programming but maybe it can be used as a reference on how to integrate those abilities.
As I am the current maintainer of the Sonos vera plugin and the one who added new TTS engines, I could deal with that for openHAB2, especially the Microsoft TTS engine I am using everyday.
Note that it is not possible in openHAB 1.x to do TTS and play the result on a Sonos device.
You have a “say” action for TTS but it plays the result on the machine running openHAB. Several TTS engines are already available in this case.
I hope it is something that will be enhanced in openHAB 2 so that we can use our Sonos.
On my side, I continue using the Sonos Vera plugin through the MiOS binding. And so I can use Microsoft translator.
Thanks. My Pi just came in and I’ll be working on setting it up the next few days. Looks like I’ll keep the plugin also.
And finally the 1.x Sonos binding is known to be unstable (making OH crashing after a certain time).
Hope is in the 2.0 binding. Not yet tested.
+1
Also using Microsoft TTS through the Sonos plugin on my vera edge but would like to have it in OpenHab
Any plans on adding the Microsoft TTS, either standalone or as part of this plugin?
I really liked the plugin on the Vera, not so much every update of the vera breaking the plugin and needing support to fix it.
As soon as TTS is working with Sonos (it exists a PR I have not tested), I will study Microsoft Translator as a TTS engine.
Since the audiosink thing got implemented, do you have enough to get the Microsoft Translator to work as a TTS engine? 
Unfortunately i read that the new Microsoft translator API now requires to provide a credit card. So I just forgave the idea after reading that.