A breather and Perspective ( A bit OT )

Colin--it was an interesting problem you presented us with and it was fun doing the math. I picked the Sony for comparison as it was the system I was most familiar with. I had an alpha camera for a while and a couple of lenses.   Finding equivalents to the Oly glass for comparison is not easy.  You are well known on this site for you nature photos, so finding equipment to deliver isn't easy.

The two lenses--the Ziess and the 70-400g come pretty close in terms of focal length and prices.  There are some tradeoffs.  The 70-400g is pretty close to the 50-200mm with the EC-14.   For $10k you could move up to a 500mm f/4. Most of what I have read about the 24-70mm has been positive.  The argument seems to be mostly about what premium do you pay for the name.  Most people assume the price and name would equal Oly SHG.

The cameras are a problem.  The SLT is a lot of fun to shoot.  It is rapid fire.  I had an A33 and the EVF was not so hot.  The features and the rapid fire shooting were a blast.  The EVF on the next generation--a77 and a57 is supposed to be an upgrade.  The EVF saves bucks on the production side (so I have read)

What I sense from you, Stacey and others, is that you just want a reason to keep the Olympus equipment you love.  An E-7--a good old-fashioned modern DSLR would keep you and lots of others happy for several years. The chances for such a camera right now are slim.  You are left with hybrid.