Proprietary? Thunderbolt and Cinema Displays are hardly proprietary. It just hasn't been common to find Thunderbolt 1/2 ports on PCs. Once Thunderbolt ups to DisplayPort 1.3 and can drive a 5K display, we'll probably see the next Mac Pro along with a Retina Thunderbolt Display.I doubt we'll see a refresh till Apple gets an Intel chipset that can handle a proprietary 5K display; I'd imagine they're tired of hawking other company's displays. The fact is that the Mac Pro is a niche device, and most people that want them and can afford them already have them. I'd wager they'll wait another year, maybe even two, before doing a refresh.