I use a lot of AXE body spray. But I live in a black neighborhood, so it's called ASK.Now, that pretty much stops me cold ... First, there's the automatic reaction: Wait, is he making fun of African-American speech? He's from the foothills of North Carolina, according to his website, and so he's presumably heard 'aks a question' enough from white people. From reading his stuff, he's clearly politically progressive (he has a prominent link to a Darfur aid group, for example), so he presumably doesn't intend to mock here.
From what I can tell about the readers of this blog, most everybody already knows that the variation goes back to Old English (ascian, acsian, with spelling variants), and that it's only pretty ([pɝrti]?) recently become so strongly associated with African-American speech, to the exclusion of white dialects, in the minds of Americans. DARE has tons of documentation on usage in New England earlier on and across the south and midlands, even specifically noting Zach's western North Carolina as having a lot of the process.
But stripping away the social baggage of the joke (right, like that could be done), it's a really odd joke. Metathesis is changing the order of the sounds in a word, and it is a notably sporadic process most of the time (although the link just given shows that it can be a 'regular' phonological process). But the notion of two dialects where in one some string XY is regularly produced in the other as YX is pretty far out there, and that this means that YX in the first is XY in the second even weirder. So, maybe this joke will kill them at the next NWAV, LabPhon or MCWOP.
Thanks to Jake for the tip on this. (Yes, the use of 'tip' there is gently distancing myself from the blogging trend of offering a 'hat tip' in these circumstances. It's the Upper Midwest and you don't/can't tip your tuque.)