That is very much a puppy thing, and really it's a good thing... much better than him acting fearful or aggressive towards new people. He just needs to learn to control his impulses, which is very hard for a puppy to do. Part of that will come with training as you teach him to walk nicely on the leash.
Read this post, in response to a question regarding the same issue you're having:
Wanting to Play w/ EVERYONE!!
- Fawn Female, born 03/23/2001
- White Female, born 03/27/2007