HP is their competitor. HP just announced that they're working on something that even if the entire thing doesn't come to fruition, likely some part will and it will change the computing landscape. Understand, this announcement is pointed directly at Dell's share holders.
Best case scenario HP actually pulls it off and they've got some radically fast system running something that looks like Linux.
Mid case scenario, they figure out how to make memsistors at scale and then sell licences for everybody to make blisteringly fast SSD's, etc. Then others come along and figure out how to put the pieces together. HP makes out like a bandit in royalties, etc.
Worse case, nothing comes out of this. HP shrugs, files a whole pile of patent applications. Someone else takes bits and pieces of it (like IBM) and does cool things with it. In all three cases HP is going to be enhance their IP portfolio and possibly make their stock worth more.
All of those scenarios are bad for Dell. Dell doesn't do fundamental science. They design motherboards that use components supplied by everybody else and crank out cheap computers. If scenario #1 comes true... HP is NOT going to sell any of this to Dell, cutting them out of the market. If scenario #2 comes true, HP is going to get these components at a price that Dell can't compete with. If the last scenario comes true, Dell still ends up being a VAR like everybody else and HP racks in royalties.
The CEO of Dell is almost obligated to thrown cold water all over this, otherwise Dell shareholders are naturally going to ask if this announcement is going to make Dells stock worth less and/or worthless.