This is just so normal, really. It's completely natural for kids to want the comfort of Mommy or Daddy as their falling asleep.
My youngest was born when my oldest was about 2 1/2, so I was working with him on this when he was younger. When I was pregnant I was rubbing his back and singing to him. I used to sit on the floor next to the bed. When baby brother was born, this was just not realistic. I really did a slow, gradual ween. I would sit next to hiim and rub his back for a few minutes but then stop when he was still awake. He didn't like it at first, but he got used to it. I starting sitting further away from the bed. Once he got used to that I started making up excuses to leave the room (laundry, dishes, needing to use the restroom, etc) with the promise that I'd be right back. I always came back, but I increased the time I was away. After doing this a few times, he would fall asleep while I was gone. That's when I started waiting quite awhile to come back, but I would still check on him. It really wasn't too long (couple of weeks?) before I was able to give kisses and say goodnight and leave.
My youngest just turned 4, and we are starting to do this with him. Yep, I babied him longer. On the nights it takes longer to get him to sleep I think to myself, "Why did I wait so long?" But really, I don't regret it at all. That time with him was one of my favorite times of day. He and I would snuggle on the couch together and watch one of my shows. He would get all comfy in my arms and slowly drift to sleep. I usually sat there with him for at least 20 minutes before carrying him into bed. He and I are both ready for this transition, but I will miss those times with him.
Good luck with your transition! But don't ever regret that special time you had with him. He is your baby, after all.