You're actually pretty lucky that he'll go back to sleep – I've known dozens of babies who wake as early as 4:30 for the day, or who still switch their days and nights at 6 or 8 weeks.
I hope you'll read Dr. Harvey Karp's material on The Third Trimester (google, or read The Happiest Baby on the Block, a terrific little book). He explains why babies are so extremely dependent on contact, cuddling, hearing Mommy's voice and heartbeat. They are still in a transition period between womb and world, operating mostly on need and instinct until they are at least 12 weeks old. Then they begin to become more alert, curious and engaged in things that are not Mom.
Your son's sleep, eating, and emotional needs will change often during the next year or longer. I'd make the most of this time while he wants that cuddling. It may feel like "forever" to you while you're sleep-deprived, but will be gone before you know it, and I'll bet you'll miss it then.