I agree.
Gmail filters, [email protected], or outlook filters make it possible to "auto-organize" incoming emails.
I'd be curious to know the stats of filter use among Gmail regular users. I have dozens of labels and sublabels as well as dozens of filters in Gmail.
For the regular Joe, I don't think email overload is a real problem.
There are a few personalities like J. Atwood and M. Arrington, who are in the fortunate situation that everybody wants to talk to them, but email works for everybody else. Also, it seems to me that if everybody would call them, or text them, or IM them (as is suggested in the article) it'd be even worse.
If I'd be in their place I'd just set up an auto-reply that says "Sorry, I'm overloaded, I may be unable to reply to your message."
I do agree that it's an interesting question how their Inbox could auto-prioratize their messages so they can respond to the most urgent ones. But 99.99% of people have no need for this feature. (Being subscribed to tons of mailing lists doesn't count, those are easy to sort out.)