Well, I don't want "crazy" things...Well, what about a 12-35 f/2.8
I rather want an UWA with a normal zoom range (16-35 preferred but I can accept shorter zooms like, let's say 16-28, 14-24) with a fast-but-normal aperture (f/2 - preferred but if isn't possible be it f/2.2 or even f/2.8 ) but with stellar sharpness, no flare and low distortions.
And I know that this is possible in a good price range.
Ironic mood off: I'll go for the 16-35 by this summer. Saving up. The wait for a rumored 14-24 and the pobable price tag helped me make my descision. So my lens set up will be "complete" again, related to my preferencies. As I am not a birder, the 16-35 will suit any need for landscapes and nightscapes/nightsky. After that, I will probaly start to save up for an overnext update of my current 5D3 (hoping for same MPs and a decent improvement beyond ISO 25k). The 5D3 is an insanely good "jack of all trades", so there might be some improvement potential: I'd be glad with 0.5 to 1 stop in RAW.
That would be the high ISO IQ of an 1Dx. Let's hope Canon get their sensor design done for upcoming releases.