I have to make a decision in the near future on a display with a time-limited work budget. At this time, the Thunderbolt Display does not qualify, because the screen glare is excessive and because I need USB 3 hubbing capabilities.
Should Apple not update the Thunderbolt Display with either matte finish or laminated glass, and USB 3, in the next couple of months, I will likely buy Dell's latest LED-backlit 27 inch display.
As an aside I would like to see Apple introduce more HiDPI modes in software. As it is, the HiDPI modes on Retina support perfectly scaled resolutions up to two-thirds of the native resolution, but the HiDPI modes through Mountain Lion with standard Macs and external displays only go to half in the built-in display menu and about 56 or 57 percent with a third-party control panel. A two-thirds resolution would yield about 1100 pixels horizontally on the 1680 hi-res matte 15 inch display and 1680 on the Thunderbolt display; both really useful for people with compromised eyesight or simply a preference for larger text. I know I'd use a 1680 HiDPI mode on the 27-inch display all the time.