Assume one makes a secure online backup of their wallet and then their laptop or device that has it is stolen. For the sake of argument assume that the thief watched the user type their wallet password in somehow, or the owner kept the password in a text file or something... what is the fastest way to transfer the funds from the online backup into a new wallet?

I would imagine this would be something like a easy online service that imports a wallet so that user is not forced to use the slower default of: find computer, download client, wait forever for the blockchain sync, then transfer.