ediblestarfish: I have both the 20mm and the new 17mm, prefer the 17mm on the E-M5.
It's just more transparent in usage for me. Maybe because I'm just a P&S person, but I like the snappier feel. Of course I'd love to have the 20mm's sharpness with all the good things the 17mm brings, but I find that the 20mm only works well when I had ample time to setup a shot before I took a picture. There's also the annoying banding issue with the E-M5 at higher ISO.
Have a handful of snaps in my gallery (with polarizer). It's PP-ed, but that's the end result what I actually get, instead of some banal test shot with nothing applied (which I never seem to do).
Yes, I'd be happy with those as a real-world test! Perhaps not quite as sharp as some I see off my Olympus 45 or my Summilux 25, but unless you're printing extraordinarily large, sharpness seems more than satisfactory. Some nice pics there.
And just as an aside, I wonder if the optical engineers at Olympus (the real experts) ever bother to read the comments of the DPReview 'experts' - they'd have a few laughs I guess!