I would not be worried at all. I have a cousin who didn't speak well until he was 5 years old, and today he is a preacher! My stepson didn't talk well until he was over 3, and he is now 14 and talks your ear off! Don't worry, just enjoy his development. He sounds very bright and will talk when he is ready.
One thing the speech pathologist suggested for my cousin was that his parents stop talking FOR him. He used to walk up to the fridge and point to the fridge, and the parents would ask, Do you want cheese? Do you want milk? etc. These questions required simply a shake of the head until they found what they wanted, and then he would nod. The speech pathologist suggested that they say, "Use your words to tell mommy/daddy what you want." Have them repeat after you to pronounce the word for what they want, and accept whatever they give as the pronounciation, and them give them the item.
Also, when my kids were little and they would whine for something, I would say, "You need to use your words to tell mommy what you want, I don't understand 'whine'. Sometimes as moms, we already know what our children want when they point or whine or whatever, and we forget to urge them to speak.
However, I wouldn't worry about developmental delays. Probably a little more encouragement will do.
Hope that helps,
L.