Originally posted by Winder Sony has not been able to make lenses fast enough for the E-mount system and CZ has not been able to design enough lenses to grow it fast enough. Olympus will be designing glass for Sony and possibly manufacturing it. We might see Olympus designed E-mount and A-mount lenses in the near future. I would love to see an Olympus made A-mount FF body.
CZ hasn't made any faster glass for the e-mount. Samsung has made some really small glass, but their only fast glass, the 85mm, is just as big as you'd expect. Olympus doesn't make any really fast glass for m4/3 either. You have to look to Panasonic and Voigtlander(or any of the manual M-mount prime makers). I think mirrorless camera makers do have some limits, based on size, they want to keep the primes portable. 1.8 is good enough for me though, bring on the Oly e-mount lenses.
Edit: misread your meaning of the word fast, in this case. I agree, I'm looking forward to more e-mount manufacturers.