Yes there is.
It's not released to the public yet, and is only available to select large accounts, and even then you need to be invited into the testing from a Yahoo rep.
I've just started using it last week at the company I now work for, and it's decent (an Adobe Air application) but no where as good as Google's AdWords editor. Copy and paste functions are extremely poor, and for many situations, it's still easier to do many edits in a bulksheet. Unlike Google or MSN's tool, you can't automatically upload changes - You actually need to export the account from the program into a csv bulksheet, at which point you can upload it into the system.