I am beta testing the new Second Life interface with voice support. It is always interesting to see how a new element is being integrated within an existing interface in order to make sure that the overall architecture remains coherent.
I found the solution to be very solid already, and while certainly issues of scalability and dependability remain, it is ready in my opinion for a wider test adoption too.
In the case of the addition of a voice to Second Life the issue of course is also that of giving up the freedom of potentially being whatever and whoever you are. And this is going to be a very dedicate issue: Even if the use of the voice system is optional, already the fact that somebody refuses to use voice will give away clues about the defense between their digital identity and their off-line identity.