Already live and implemented ?
Yes. Go to debug windows (console) and enter getpeerinfo.
It should list onion addresses instead of regular IPs.

[
{
"addr" : "vmpxbxaljhe2pef7.onion:4437",
"services" : "00000001",
"lastsend" : 1404913788,
"lastrecv" : 1404913774,
"conntime" : 1404913748,
"version" : 61001,
"subver" : "/Junaeth:1.0.0.1/",
"inbound" : false,
"releasetime" : 0,
"startingheight" : 2008,
"banscore" : 1
},
....