Today see's Ati's Crossfire launch and as you might expect all the big hardware sites have published their take on things.

[H]ard|OCP, Anandtech and The Tech Report are just a few.

The general consensus seems to be that it's currently not quite as good as nVidia's SLI, refresh rate and resolution limitations being a major cause for concern.

The Tech Report

Ultimately, these things shake down to a few essential truths. As a whole platform or solution, CrossFire isn't as good as SLI, but it's probably good enough. CrossFire's true fate and desirability will be more than likely determined by ATI's next generation of GPUs and by the master cards that will go with them. If those products are good, CrossFire should succeed. If they're not, folks will probably decide that CrossFire isn't worth the hassle.