The idea is technically sound. It's called ghosting:
QUOTE
Ghosting
Ghosting or "to ghost" is The act of one or more dead players spectating an alive enemy player, with the intent of revealing his or her actions or location to their alive comrades, giving them an unfair situational advantage. This is achieved usually through a voice chat program, such as Ventrillo, or an IRC client.
Ghosting may also be referred to as as "Venting" in popular games like Counter-Strike. The term derives from the most popular method of ghosting in Counter-Strike, which is to use the program Ventrillo, "venting" is short for "ventrillo-ing" meaning Using Ventrillo to ghost
I think they have implemented it poorly though, while I am for the result - it can definitely be done in a way that doesn't ruin peoples gameplay. For instance, when you die then you can only spec first person of people on your team, that way you don't get to see any more or less than them.
I used to play CS a lot and it did get on your nerves when just playing solo and there'd be two or three clan members tagged, that were obviously using TS2 to communicate after death and when it came down to 1 v 1 you were just at such a disadvantage.
A lot of the fixes implemented for CS though were server side configured, i.e. it was up to the server admin what gametype they were hosting.