Lenses that are new in 2012 and are actually shipping and that I have reviewed and used extensively.
I am very picky, so this list is short.
Zeiss 15mm f/2.8 Distagon (for Nikon or Canon DSLR)
Zeiss 135mm f/2 APO-Sonnar would likely be on this list, but it has not arrived as yetx.
Canon 24-70mm f/2.8L II
Canon’s best wide angle zoom, ever. Superb contrast and sharpness, though with some unavoidable field curvature.
Olympus 75mm f/1.8 ED (Micro Four Thirds)
Fast but compact lens offering superb sharpness.