Their headline is misleading because it doesn't address a flaw/bug/feature in iTunes that fails to permanently attach fetched album art to the actual ID3 tag. They offer an interesting tip, but I have thousands of songs. Unless there is a way to automate this, I can't see myself following the outlined steps over and over again..
I will say that I think OneTipADay may have discovered why iTunes CoverFlow doesn't work as well as the real CoverFlow (on the Mac, at least). It's been driving me crazy wondering why album art isn't preloaded. iTunes always seems to wait until I scroll the album by before loading it's artwork for some albums, but other albums' art was already there. I never dreamed that iTunes didn't actually attach the artwork to the ID3 tag. They obviously store the album covers in cache instead. I suppose Apple's method reduces file sizes, but the trade off is forcing us to wait for the album art to load. Personally, I would prefer attaching the art to each file. The point of CoverFlow is eye candy. What good is eye candy that makes you wait?