TTS in Microsoft Lync

According to

"State-of-the-art speech technology now in 26 languages provided by the updated Microsoft Speech Platform, a zero-royalty, enterprise grade server based speech platform that ships with UCMA 3.0 and now adds VoiceXML 2.1 to UCMA needs. "

So you can develop UCMA 3.0 based application with TTS function in 26 language now.