We got a call almost one year ago for a little guy that was 2 1/2. He was the same way, went right with the cw, came right to us not afraid or anything. The first couple months he held up his arms to anyone. The gas man came to our house and fs held his arms up yo him. Now almost 12 months later, he's just like any other 3 yr old. He's bonded very well, now only runs to dh after sunday school etc. I haven't seen him just want to be held by just anyone in quite awhile. Just needed a family to bond to I guess. I'm glad we got to be the family!!!
In other words...I wouldn't worry yet!
Take Care,
Mommyto9