Morning nap; yes, I will wake them. Otherwise some would happily sleep through lunch, etc and then not nap in the afternoon.
Afternoon nap depends on the kiddo, and our current schedule. If I know that they were put to bed a little late the night before, or got up extra early, they can nap a little longer. I will wake up the 2.5+ year olds, because I think 2-2.5 hours is a good nap for them. Any longer and it can start to interfere with bedtime. But the littlest ones have been known to take 3 hours or so. And those days are GREAT!