Our oldest was 3 years ol on her first trip, our middle was 9 months and our youngest was 10 months on their first trips. Our only regret is that we waited so long to take our oldest. To atch our babies take it all in was priceless. Do they remember the trips, of course not, but they don't remember any of the wonderful things we did with them at those ages, but we do, and will never forget them.
My greatest Disney memory was of my DD who will be 10 next week. She was 9 months old and teething. We were at breakfast at Pluto, who she was drawn to anyway, came over to her. She reached out and grabbed his tongue and started teeting on it. Pluto stood there for several minutes while I teared up, snapped photos and my DH took video of it. After that we went and bought her a small stuffed Pluto who, despite looking ragged and has a lot of his tongue nibbled off, and despite having gotten other Plutos since, she still sleeps with every night. She doesn't rememeber it, but she loves to see the video, look at the photos and hear the story over and over about the day she got that Pluto.
Of course your baby won't remember the trip, and if it was their only chance to ever go, sure, I'd say wait, but you will remember and I doubt you will ever regret seeing disney through your baby's eyes.
I loved Disney as a kid, but I love it so much more though now as an adult as I see the joy it brings my kids. At each different stage it brings different joys. We have gone with infants, toddlers, young kids, older kids, tweens and on our last trip our teenager. Each stage is magical in it's own way. Go and enjoy it so you don't look back and wish you had!