It should last at least 60k miles and longer, though a very small number of them have gone out sooner than the 60k mark
Most of the reviews I have read on the Aveo's online say they have been going out around the 50k mile mark BUT that was on the 04-05 models, I think GM switched belt Co. in 2008.
05 Aveo LS Auto - $500 Daily Driver
94 Z71 - Other DD
00 Corvette - 550HP Weekend Toy
10 Infiniti G37 - Wifes DD