I can only speak from my experience - my daughter is almost 8months and she started nursery at six months and absolutely loves it. It is personal choice really, and I think most childminders will have other children to look after and usually take the child(ren) to local playgroups to encourage interaction anyway.
Nursery is right for me, I get a report at the end of each day telling me what she has done, eaten, slept, pooed and weed and when! She has little "friends" all her own age - her class goes frm 3months to 14months, and she has learnt so much in the 2months she has been there. She has a little friend called Tom who is three weeks older and they sit chatting to eachother; she is delighted to be there and it's a weight of my mind to know she has settled in. Also, although this changes from nursery to nursery, ours includes meals, milk and nappies.
Obviously this decision depends completey on your personal views, your child, your finances (nurseries are often more expensive), etc. We have been lucky because Emilia is a very sociable child, and interacts well, but I would think that a nervous or quieter baby might find nursery a bit too much.
Best of luck with whatever you choose though xx