One, slightly arcane UI tomfoolery is the rearranging of the columns.
Left-hand navigation columns have been common since the very earliest days of the WWW. Later, it became standard to have a main section in the middle column and on the right-hand side, further links and details. The placement of the content in this third section is so typical of online media that it has become convention.
It isn't just online newspapers with their millions of pageviews that adhere to this unwritten dogma. Facebook adopts this principle too, with navigation top and left, the main content in the middle and extra gubbins to the right.
So, should we blindly follow what everyone else has done before? Well, actually, in this case, yes. Conventions are good for User Experience. A word on a page, which is underlined and in a different colour, we know by convention links to another URL. By the same token, we know that stuff on the left is navigation and stuff on the right is your side salad.
Twitter is asking us to drive on the wrong side of the road.