Dell just about now released their 4K displays. Yay! \o/ Coming in at 31.5", and dubbed the UltraSharp 32 (or Dell UP3214Q, if you fancy that). Unlike the old 30", these are is 16:9 like the 27". Yes, they work with the 2013 rMBP and the new Mac Pro. Yes, they also have an USB 3.0 hub. Current Dell price is $3,499.99. Dell also updated the 24" model with a much slimmer bezel, 16:9 aspect ratio (1080p instead of 1200p) and an USB 3.0 hub as the UltraSharp U2414H.