"Sun Marketeering droids" if only Sun had a marketeering department then perhaps the stock would be better. Getting back to the point .... the technology does the talking.
Niagara is pushing the envelope with built in with 10 Gigabit, line speed encryption and virtualization built in as standard in most cases. Even the PCI Express IO is on the silicon. All that means fewer parts and points of failure, lower costs, and vastly reduced power consumption.
Again to reiterate - this is Sun's ENTRY level SPARC range and focussed on massively parallel network centric workloads. It is also suitable for many standard application workloads up to a point. For 80% of the time it does the job very well. For the other 20% you have other products in the SPARC range.
Just one last point - if the thread speed was upped to 2GHz then the low power advantage would be lost. The 2GHz + version is called Rock.
The technology is different - heresy to some even - but it gets the balance right between price / massive throughput and very low power consumption and is very popular as a result for those who care about such problems.