On the subject of wifi radios, there is a group working on hacking the
Reciva Baracuda module, which is the smarts in radios like the
Acoustic Energy Wifi Radio, Sangean WFR20, etc. One of the goals on
their list is an accessible interface to these radios. (I expect
Espeak would be a nice small synthesizer to press into service?)
Anyway, some smart people might check out the project at
http://sharpfin.zevv.nl