Good question. KQ is a trouble hand if you're facing a raise. However, it is usually safe to assume you are not dominated if they limp in (since most players raise the hands that have you dominated most of the time). In this situation it is more likely that you have some of the other players dominated (if they limped in with a hand like QJ).

I was playing some (short handed) tables the other night. My friend was watching, and he asked why I raised AT on the button after a couple of limpers. I told him: "because everybody raises AJ".

By the way, I just started playing some limit (I have a long and noobish thread about this in the limit forum), and I'm trying to learn not to raise here.