Hi, I'm really happy about this lens anouncement
There was no really good 50mm lens available yet. For landscape photography in this focus length I used so far an old medium format tilt-shift lens or the TS-E 45mm. Both are mediocre but you can't shoot every scene with a TS-E 24 L II or a TS-E 90mm. The tilt-shift design offered at least proper corner sharpness and less hassle than an ordinary 50mm lens on a panorama head.
I don't really mind the size or the weight of this lens. To have AF would be a bonus but I don't really care! It takes me normally several minutes to set up my equipment for a landscape shot, so I do have time to manually focus in live view. And for street photography, events etc. I prefer the EF 35L yet. For such occassions Sigma will hopefully update soon their 50mm lens.
The only negative aspect is the price. 2500-3000 EUR would be great. Now it will take a few more months of saving.