If it's priced equal to the MX than it looks like it could be good compettion for the MX. Both cards have their advantages and disadvantages.
Radeon has superior image quality, and better 32 bit color, better DVD support, and is better equipped for future games.
On the other hand, the MX has better drivers, better 16bit color, much better support for FSAA, and also has twin view support, and lower power requirements.
It looks like it really comes down to a matter of what features your after, assuming their priced equivalently.
Myself, I still don't see much of a difference with 32bit color, and the better DVD playback isnt very important to me. So I would choose the MX over the Radeon. I also upgrade enought to make the longevity of the Radeon a non factor. I alos like the lower power requirements of the MX.