I would say plan to take the baby, but I will also caution you that not ALL babies at that age love everything about Disney.
We took DD at 8 months old and she was frightened by a lot of things. She DID NOT like the characters, even at 8 months old. Cried every time we got near them.
While we were able to take her on lots of the rides, many of them frightened her. Most of the rides at Disney are accompanied by loud soundtracks. She hated the noise. Even if I tried to cover her ears, she would cry. In fact, we have some pretty funny video of her wailing through most of the boat ride in the Mexico pavillion at EPCOT. It was just way too loud for her.
She also did NOT nap in her stroller...too much to see, too much going on. We had to return to the hotel room if we wanted her to nap.
Even with all of that though, we had a great time, and there were things she enjoyed...like strolling through the shops, or through World Showcase at Epcot. She enjoyed watching all the different water fountains and was "ok" with the characters, if they kept their distance.
I just thought I would offer up that not every baby is alike and you might want to consider your baby's temperament before you make your decision.