So, I have a newer loaner today. VIN 44xxx. I was skeptical about the higher res before, but now I'm convinced. I compared it side by side to an older car and this car definitely has a higher resolution screen and the thin bezel.
HOWEVER---
It's obvious the tegra 2 driving this display hasn't changed, and isn't up to the task. The frame rate is quite low and inconsistent. The power meter "sticks" a lot and skips around when changing fast. Someone earlier in the thread (brianman maybe?) speculated this was the case, and I think they are dead on.
Also, it's obvious not all of the art assets for the display have been updated for the new resolution. Proportional fonts around the speedometer and lower info bar look nice, but you can see aliasing for bitmap assets used for some of the sub displays like trip and power usage graph. The car graphics look nice, but I assume they are using the same assets the center console uses. Perhaps they will update all of these in a future software rev.
To be honest, it doesn't add much. Sitting back in the seat it's very difficult to tell the difference other then the juddering graphics on the higher resolution display. I don't think I'd want an upgrade until they beef up the chip driving this new display.