The release announcement isn't particularly exciting. "Scientific Linux 6.0 is now officially released and available. We want to thank everyone who has contributed, tested, and given us feedback. Without everyone's contributions, help and testing, this release wouldn't be as good as it is."
More information is also on the SL6 web-site. Scientific Linux is available in 32-bit and 64-bit builds.
Benchmarks of Scientific Linux 6 are already available on OpenBenchmarking.org.