Valve has added a Recently Updated page to Steam, displaying "new and interesting updates, features, and/or content additions" to games. Take a look for yourself. The intent here is to give developers another platform from which to communicate with their audiences.
It's got the added benefit of showing would-be players which games are seeing continued, worthwhile support. Scrolling through this section reminded me that I forgot to buy Desktop Dungeons, so there you go. My initial reaction was that in the wrong hands, the feed could be nothing but the same few frequently-updates titles, but that doesn't appear to be the case.