Depends on the situation. If you can get it all-in with just one villain, the
odds are way in your favour, although I have seen AA go up against AA, and I've even seen that happen where one beat the other by hitting a flush (but I digress).
If you're short, you're more likely to get more callers, but you ARE SHORT after all, so you can't not play Aces in that situation, unless you've been in a tournament for hours and you're one player away from being ITM, maybe.
Now I'd be more likely to play the hand out with a big pair other than AA. Take yesterday for instance - I got it all-in pre-flop with KK and lost to AA. Mind it was a low, dry flop, so I was probably gong to end up putting it all in the middle anyway.