As you know every child is different, but here's what our kid (now 2 1/2) does:
bed between 6:50 - 7:00 PM
wake around 7:00 AM
nap from 12:30 - 3:30 PM
We, too, reached a point where when we put him down he'd be playing/talking in his crib for another 30 - 60 minutes. This was when he was still going to bed around 6:30 - 6:45. We started the nighttime routine about 15-30 minutes later and it seemed to make all the difference in the world. When we put him down at the later time, he would talk for about 5-10 minutes and then clock out for the evening.
If you choose to make any change, just do it gradually. Also, if he seems content and he isn't Mr. Cranky Pants then everything is probably cool with him. Some people don't fall asleep as soon as their head hits the pillow - I know I like to unwind, relax, and don't fall asleep sometimes until 30 minutes after I get into bed but it's not like I'm restless or lacking sleep. Maybe he's just using the time to wind down, close out his day, and prepare for sleep?
Good luck to you - sounds like you've done a great job guiding his sleep schedule!