My 3 year old DD was getting this way...she was the stall master, would goof around at story time rather than sit still and listen, want one more hug and kiss from daddy, or a drink of water, etc. I moved her bedtime up but also made it clear that this is what the routine was going to be, no exceptions. Made sure she had her sippy cup and let her know this is the last hug and kiss for the night. She's in preschool twice a week so I borrowed a line from her teacher and remind her at story time that I need her to be a good listener. And just in general saying NO to a lot more things ("No, I am not going to sit in the chair after you are in bed - it's time to go to sleep." "No, you get 2 stories, and that's it."). Sometimes she is still talking in her bed for a while after but this really doesn't bother me. At least she stays in bed. And she still takes a 3 hour nap every day.
I actually posted on here about this issue I was having with her, if you would find it helpful:
http://www.mamapedia.com/questions/15053521088988446721