I don't think there will be a big gap between the Ps4 and 720, Sony may be in a bad position financially but that does not stop them pushing out new technology all the time in areas where they are losing money, so for their gaming sector which is often profitable I would expect them to continue to invest a lot of money into it.
If the PS4 comes with a standard controller than It will definitely be substantially more powerful than the wiiu due to all that money spent on bundling an expensive controller will be spent equipping the console with better hardware.