Is it just me or would powersliding be an oxymoron? Your front wheels are the ones powered by the engine and thus drive the car, yet in a FWD car you can only "powerslide" when applying the e-brake to induce extreme oversteer. The driving wheels are not the ones inducing the slide. Now, you cannot "drift," which is simply "a gradual deviation from an original course, model, method, or intention." I really think drift would be the proper term for e-brake application on non-drive wheels, and powerslide would be the proper term for motorsport drifting. Either there's confusion with the original word's meaning - drifting that is - due to the inclusion and rising popularity of the motorsport itself, or the terms are synonymous and intermixed.
Then, think about the term "power braking," in which the drive wheels overcome the braking force of the pads and the static friction between the tire and road to allow them to rotate while keeping the other non-driving wheels still. Wouldn't powersliding simply be using the power of the engine to drive the powered-wheels in order to break the frictional force present on the tire?
That's my reasoning.