A.P.
Dear L.,
My daughter, who is now 4 1/2, started preschool when she was two. Before that we did Gymboree. Putting her in preschool was the best decision my husband and I ever made. She really needed the socialization since she is an only child, and I needed a bit of a break.
I learned from our Gymboree experience that it appears the children are not paying attention and just goofing around, but what is being taught is actually going in. It rattles around for awhile then comes back out when you least expect it. The instructors at Gymboree told me that it would seem a child spends all of the class staring out the window, but when they got home they would "perform the whole class." So your son will get something out of his preschool experience, even if it seems he's just playing with "different" toys. At the least it will help you learn to seperate from each other.
One woman told me a story that she didn't want to put her son in preschool because she wanted to spend all the time with him. By the time he was four he was begging to go to preschool so he could be with other kids. I thought is was rather selfish of her to try to keep her son all to herself.
Since his birthday is in November, you might want to wait until this fall for him to start preschool. Of course, the preschool registrations for next fall will start in February (it does at my daughter's school). The teachers will appreciate that he is a bit older when he starts, and he'll be even more ready for school. I recommend three days a week. The children get used to it faster than just two days a week.
Hope this helps!