That's what I would do, why make the transition easy? I say screw them, tell your boss to train your replacement!

Don't be like those poor chaps at Siemens that took the severence to train their replacements, and later complained that their Congressman sold them out http://www.outsourcecongress.org/USA/tata/siemens_ assignment_bonus.jpg. By agreeing to the terms of the severence, they in part sold themselves out. Don't play the game, just walk away.