Yeah it looks like the people who actually posted analytics data in that post are backing up the claim that 1024x768 is no longer the gold standard even though it is still perceived that way..
I wouldn't be disregarding 20% of my users in a hurry.
I design more than I do backend stuff these days, and I don't think I'd even want to be designing much wider than 950px. More space can quickly mean more info and thus a more confused message for visitors.
From W3: 76% have a higher resolution than 1024x768. http://www.w3schools.com/browsers/browsers_display.asp