ATi, after getting beat up by driver optimizations (for 5 nVidia picked games) for the GTX 260 (216 cores), is hard at work developing its own optimizations for their 4xxx series of GPUs.
The new drivers (8.12) should hit in December and may bring the 4870 back into the lime light if things work out better than the last two releases.
Fudo has the scoop on that here.
The new ATI Catalyst driver 8.12 should be available on December 10th and it will bring optimization for the titles that Nvidia has a right to gloat about.
We managed to find out that some of these optimizations are also going to wait for the next Catalyst 9.1 which should probably come sometime next year. The optimizations are going to influence both single board and CrossFire configurations and the only issue are the titles for which Nvidia apparently had more time to optimize than ATI.