I have heard rumors that there may be a third version of this lens coming out sometime soon. If it is true are they thinking about improving its mount and construction? Thanks
Probably just wishful thinking, but then again with a 1.6x crop factor with consumer DSLRs Canon may consider it a potential best-seller as a short tele portrait lens... and they're probably right if it has the build quality of the Mk.I! Hope you're right about this as I could do with such a lens myself!
FWIW, I haven't seen that rumour. Personally, I doubt we'll see a 50/1.8 III, but that's just me. And the standard disclaimer applies for rumours: anyone who knows the truth will be bound by non-disclosure agreement and will not be able to tell you one way or the other.
It is something that would be nice to see, if they made it a bit more durable than the mk II, and gave it some form of USM with FTM (micro-USM II perhaps). For now I'll just stick with my mk I.