These things usually only come up for order when they know they will be shipping fairly soon so this is a good indication that the new MKIII Extenders (teleconverters) will be hitting stores soon.  Originally slated for a December release it seems this may slip to January.  B&H has them up for order now

Canon Extender EF 1.4X III

Canon Extender EF 2X III

I wrote about these when they were announced earlier in the year at Photokina.

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