This article is kind of missing the point on why the iPad experience is missing that "Pro" feeling. Yes multitasking could be much improved, but having the iPad locked in to the iOS ecosystem with the AppStore and abstracted/obfuscated file system makes it very difficult to use as a computer replacement, at least for me.
I think this is more a matter of having a different view of what “Pro” means/vision of where iPad should go than about the iPad not being pro.