If you try to go once a year anyway, then I would go for it!
We took our son at 7 1/2 months and 12 months. Both were great trips, and a lot easier than I thought they would be (we drove, but we also took a different trip with him flying right before the 12 month trip).
Here are some things that really helped:
-A front carrier. We kept him in the stroller most of the time, but strollers are not allowed in lines. A front carrier was great because he could be in it in line and stay in it on the ride. It was easy getting on and off rides, and he got to see everything facing forward. The only ride we were asked to remove him from the carrier was on the carousel.
-Baby Care Centers. It was a lot more calm for diaper changes there than in a bathroom. That said, we also used the companion restrooms a couple of times if we weren't close to the baby care center and had a two-person diaper job.
-Johnson and Johnson hand and face wipes (love these!) and disposable plastic placemats if already starting on table food (they come in Mickey versions too!). Those were my lifesavers for keeping everything sanitary.
Trips at both ages were awesome! At 7 1/2 months, we got his first Mickey Ears Hat, and he actually recognized Mickey during the character meet (we had been watching Mickey Mouse Clubhouse and an old Disney sing-a-long,
Disneyland Fun, which shows the characters in the parks).
Our 12-month trip was filled with tons of firsts - first taste of ice cream (France at Epcot), first character meal (Tusker House - and we've gone back for every birthday since), first Mickey waffle (he ate like 4-5!), and my favorite: he started walking at the Boneyard at AK.
So go for it, and make some great memories! Since you go at least once a year, it's also a great time to start some family traditions.