[CentOS] EL 6 rollout strategies? (Scientific Linux)

I was wondering what feedback might be offered by the CentOS community on their experiences using Scientific Linux?

I'm a long-time Centos user, and am basically happy with CentOS. I understand there are delays getting EL 6 out. We have been long anxious to roll out EL 6 as soon as it's ready, but our time window for rollout is looming and we will need to act. (for business reasons, we need to rollout over summer, before Aug 1, we need to start regression testing now!)

I was once a WhiteBox Enterprise Linux user and switched to CentOS 4 without issue, and am assuming that I might need to do something similar if we decide to go this route.

Any feedback is appreciated!