I agree. Talia started Daycare about 6 months ago and she absolutely loves it. She is an only child as well and wasn't getting much contact with other kids. She is a mummys girl but first day there she just waltzed off to play in the sandpit. I told her I was going and she just waved at me said "Bye mum" and that was it. No tears or tantrums. The owner of the child care was a bit stunned as she said there is usually some tears the first day but no Talia was too excited and loves every day she goes.
She goes 2 days a week which I find is better than one which she started with. So I reckon go for it. The teachers will soon tell you if the don't think he's coping or needs you to hang around for abit. Ohh and enjoy the break you get and don't spend the whole time stressing about how they are going. :P