I do look in here still and do miss posting in this thread but all Leica M now with no regrets.
The 200 2L is definitely one of Canon finest efforts when it come to glass. I had mine for 8 years and got about what I paid for it when to was new when I sold it so if you pick one up you probably wont loose $$$$ like you will on Canon bodies and most other Canon glass.
I'm late to the game on ownership. I suspect canon will release a new version now that they have new coatings/optic formulas for weight/size savings. The new 3 option IS also. They release a new one it'll be the same 5,600 new and will drive the used prices on the 200/2 down to the mid 3k range.