I'm sorry, but I can only presume you are referring to a lack of ultra-wide prime lenses. The the 7-14mm Panny is based on the 4/3rds Zukio 7-14mm zoom which is an outstanding optic which I have been using since 2006, and am currently using this on my E-M1 via an MMF3 adaptor; unfortunately, unless it's it's in lousy condition, stolen or/and being sold by an idiot, you won't find one of these for $500! Apparently, Olympus is currently working on a m4/3rds f2.o version of the 7-14mm, which might appear around 2015.
The 7-14 doesn't work for me as it lacks the ability to use filters.
That said, after a bit of experimenting, I figured out that 12mm is ample for what I need. So, I am getting either the 12mm f2 or the 12-40mm f2.8.
I thought the 7-14mm PRO was going to be f2.8, not f2.0. I believe they are also working on a fixed 9mm for the PRO line.