Lensrentals got the 120-400 OS Sigma and the Canon 200/2L IS in.

[Roger]

Personally I'm waiting to try the 150-500 OS.

Sigma for Canon only right now:

http://www.lensrentals.com/item/sigma-1 ... 4.5-5.6-os

Canon 200/2L IS:

http://www.lensrentals.com/item/canon-200mm-f2.0-is

(only starting at $335 for one week)