The redesign that Twitter is testing closed form is a mix between Facebook and Pinterest.

Twitter is not just a social network that makes design changes often dramatically, but when done, it does tend to be dramatic and generate much review. Part of the Twitter culture is changing small elements in this social network, for example the last change of Twitter could be considered a good redesign since the site does not change completely, but if it improves the overall look, adding more customizing colors and backgrounds, which is curiously what people most like to change.
Although keep in mind that this is a test and not have to change as well be the end of the listing, the redesign is drastic, becoming more profile in a cross between Facebook and Pinterest.