I think this question was posed at some point, because it's clear that some of us would like to take advantage of that massive resolution whenever displays that carry it become available on the market at some point. And it seems like 10.9 DP does include preliminary support for it. In fact, it works even via HDMI, so we can save the Thunderbolt buses for other peripherals. Source: http://blog.joemacirowski.com/archives/1242 Very nice! I think I may end up keeping my rMBP 15" and skip the Haswell update after all. Saving up for a 4K Retina Display (or whatever Apple may call it) looks like a more logical step. It's nice to know a machine I bought 11 months ago is still going to be useful in the future.