I have a MacBook Air (Late 2012), which has the new Magsafe 2 power connector.
I would like to use the power adapter with my 15" MacBook Pro (Mid 2010).
Is there an adapter for it? A quick search on Google didn't yield anything.
Apple only produces an adapter to connect the original Magsafe to Macs with Magsafe 2. It doesn't provide one to go the other way around. At the moment I'm unaware of any third party product that does this (and given the lack of third party Magsafe accessories in general, I wouldn't expect one any time soon).