Hope this hasn't been brought up before, but here goes: The following assumes that between now and when the new 'retina' displays are introduced next month or so, the Thunderbolt spec won't be updated. The maximum useful throughput (goodput) for the current TB spec is 8Gbit/s per direction/per channel (8b/10b encoding). This is below DisplayPort 1.0/1.1 spec of 8.64Gbit/s. What this means is that there is a ceiling on the size of the display that can be driven with a Thunderbolt cable. And seeing as the TB Display is Apple's flagship external display, it will likely see updates to the resolution, matching, or at least exceeding other displays available in Apple's range. If Apple's brand new 'universal port' spec that they championed, and had a headstart with, couldn't work with their new high resolution updated TB Display, why bother with updating the display resolutions at all. So, with all that out of the way, the maximum resolution is: 3072 x 1728. 60 fps * (3 * 8) bit colour * 3072 * 1728 = 7.644 Gbit/s. This is all sheer speculation, but grounded in my form of logic. There's nothing stopping Apple from using 'retina' displays in internal screens that are beyond the size above, but to me it just doesn't sit right. Suppose a new Mac Pro is released and all Apple sells are these new 5120x2880 TB displays but you're forced to run them at 2560x1440 because that's all that TB can supply. You could argue that the GPU's in them would have their own later spec DisplayPort that would drive them at full res...but no spec handles that amount of data. How much data? 60 fps * (3 * 8) bit colour * 5120 * 2880 = 21.23 Gbit/s. You'd need two HDMI 1.4 spec cables, or 3 TB cables to power that beast.