It doesn't have to be this way.
Dell: Manufacturer
(UltraSharp): The high-end moniker
XX: Size
Ultra HD: The name for that resolution
Monitor: What it is
Maybe it's because I'm an engineer and not a normal person, but the naming scheme seems quite reasonable. Way better than the utterly indecipherable "Dell 324y5943X" crap you get with some other manufacturers. The resolution name, "Ultra HD", is stupid, but that wasn't Dell's decision to make, and the industry has been naming resolutions like that for twenty years.[0] (VGA, SVGA, XGA, SXGA, etc...)
[0]: http://en.wikipedia.org/wiki/File:Vector_Video_Standards2.sv...
Also, how about just a simplified product line like, I don't know:
Dell UltraHD 24" Dell UltraHD 32"
Along the lines of Cinema Display.
Anyway, as for unifying the product line- Dell being Dell, that would mean simply cutting the UltraSharp product line, which I would consider a loss.
It is unfortunate for dell that the 2160p resolution got labeled something so similar to their existing brand.
Macbook
Macbook Pro
Mac Pro
These names have been with us for, what, nearly a decade?