What gamepad features are there at all, apart from, well, being on the gamepad? IIRC there's a new augmentation that lets you see enemy details - shouldn't be too hard to port. Other than that, all I know is that the gamepad is basically a UI hub and HUD.
The improved boss fights should be patched in by plain principle. It would be dickish not to, seeing as how this is a plain admission that they were a botch job. What I'd like the most though is that 8 hours of dev commentary. As someone who followed the game's development... with... considerable attachment... I'd really like to listen to a post-mortem as the game plays.