Well, considering that the normal maps won't work on your rig, you should end up with a fairly decent performance with the exception of a few missions. It is tough to tell, because it's been ages since I ran Saga on a similar system, it worked fairly well though.
Shader 3.0 is my main weakness, as I can run Mass Effect 2 on this system but the shader requirements kill the frame rate making it hard to aim in the game. I know I am reasonably safe with shader 2.0 and under for games, but gets to be very questionable as to whether or not a game will run on my laptop with playable frame rates when shader 3.0 is used.
For got to ask what about phsyx, if this games uses this feature then I know the game will not be playable on my laptop Guaranteed?