Test retirement age of all batsmen to score over 10,000 runs -
Tendulkar 40
Ponting 38
Kallis 37
Dravid 39
Cook 33
Sangakkara 36
Root - TBD
Lara 37
Chanderpaul 41
Jayawardene 37
Border 38
Waguh 38
Gavaskar 37
Khan 39
Root doesn't play T20 really, no one plays much ODI anymore, so he's got a really good chance of staying at the top until he's in his late 30s if he wants to. He's getting about 800-1000 runs a year and he's about 100 runs behind Cook to be Englands best, 1000 runs behind Ponting in #2 and 3700 behind Tendulkar.