Congrats on the new body. I too went from the 7D to the MKIII. I was going to keep my 7D as a second body, but after seeing the results of the MKIII, I quickly changed my mind and sold my 7D last Thursday.
Lightroom 4.1 will work with the 5DMKIII RAW files. If you don't use LR, then another workaround is to download Adobe's DNG converter. Version 6.7 will read the MK III's RAW files.
Here's one of the first pics I took with my MKIII. Straight of camera. First time I ever made Explore on Flickr.
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D-2-C, on Flickr