On one of my recent trips to Walt Disney World, I was able to experience the new meet and greet for Mickey and Minnie at the Magic Kingdom's Town Square Theater. I went close to midnight, so the majority of the kids were already gone and that meant no wait time for me. I literally walked right through! It was great!
Overall, I thought the room where you meet and take your picture with Mickey and Minnie is much better than the one in Mickey's Toontown Fair. It has so many intricate details that really bring the whole experience to life. What is lacking is the experience you used to get while waiting in line at Mickey's Toontown Fair. There, your entire surroundings brought the experience to life with giant pumpkins and old Disney cartoons! At the Town Square Theater it is basically just white walls with red carpet and ropes - it makes me glad that I didn't have to wait in line.
Below are pictures of what the experience inside the room with Mickey & Minnie looks like. I think you'll enjoy them.