We have been offering them for a bit now as customer orders, but they're now a standard product offering, the Xeon X5660 2.8Ghz six core processor in a dual processor configuration. These servers come with 12GB of RAM and 2x 500GB hard drives (using our current RAID special) for $599.95 a month. This can serve as a great option to those currently running their Xeon 5520's to the max or simply need some additional headroom as it'll get you ~25% more processing power per core and 50% more cores for a nearly 90% performance improvement, assuming what you're doing can take full advantage of the additional cores. With this offering, you can get nearly twice the processing power and twice the RAM for just a 50% higher cost for the base system.
These servers can be ordered via our usual dedicated server page: http://steadfast.net/services/dedicated.basic.php