Games giant Valve attended a developer conference in the Netherlands called Indigo last month, in which Valve's Alden Kroll gave a presentation on Steam and some of the changes coming to the platform, and among the slides (all of which can be found on Valvetime) there was one commenting on the UI.
There's not much to go on other than the text: "overall UI refresh and update coming", but the phrase "overall" may well indicate that the whole platform will be revitalised, and that the way Steam looks now may well be on the way out. On the same slide there's also the note that, "for developers, biggest changes are in library."
Does Steam need a UI change?