text to speech in webplayer

Hi, I was wondering to add a simple text to speech to my weblayer build, but after researches it doesn't seem possible also because you can't use webservices in webplayer build (is it correct?) (i could use Google Text-To-Speech (TTS)) I need a clarification: why unity use .net 2.0? .net 3.5 would be enough to solve this problem thanks