(The 'D' means double)
Especially when it says "...limitations with pumping DC power from electricity plants, as it can only travel for about a mile before the energy supply begins to weaken."
DC power distribution systems exist that send Megawatts for miles at high efficiency.
However, there are many reasons for using AC generation and distribution (look them up on the many websites available, actually Wikipedia is quite good at factual engineering things like this, sorry but it is) so that's why we have AC as the publicly available grid power source.
The advantage these people seem to be suggesting is replacing all the individual mains AC-DC converters (switch mode power supplies and also DC-DC voltage converters) with some kind of giant site based AC-DC converter which then feeds DC power to the server racks, hence to the motherboards/hard drives etc. The idea behind one giant site based 'infrastructure' converter is that it can be made to be more efficient than any much smaller converter that works on the same principles (but only if it operates at near maximum design load all the time). However, existing switch mode AC-DC power supplies are already quite efficient (I believe in the order of greater that 85%) so its hard to see where they can get 40% power saving from. It may just be possible that they mean 'reducing power wastage by 40%' which would be a good thing of course.
Further, having generated local infrastructure sourced DC, at various different voltages (or else you'll need local multiple DC-DC converters in the server racks) you then have to distribute it around site on meaty copper busbars, due to the high currents involved when using low voltage to deliver power. (Lets not get into the consequences of shorting flashes with DC power, I once blew a hole in sheet aluminium with a powerful DC source.)
"..it said it has developed a technology that takes the AC power provided by utilities and converts it into DC."
Well, that was done a long time ago (think rectifiers, capacitors, and er, switch mode power supplies), so unless they've developed something truly new and wonderful that has a conversion efficiency in the late 90's percent for a compete system, I can't see what they are offering.
"Validus then pumps the converted supply out to servers specifically designed to run on DC power."
Hmmm, all servers are designed to run on DC power, that's why they have switch mode AC-DC power supplies bolted inside them somewhere so they can obtain their required DC power from the universally available AC grid supply. We're back where we started with Validus providing a massive infrastructure DC power source. (See above).
I think I'll stop now.