I escalated this exact issue with some folks I know at MS, mentioning particularly that Apple, to their credit, had already jumped on it..the reply from the codec team was that they were aware of it and would release an update at some point. In other words, we'll get to it.
They didn't mention that there would be an update on 4/19, so that is a hopeful sign. Before any codec was available from MS, I bought the one from Ardfry. It worked just fine. I just checked, it's not updated for 5DIII, either.
FWIW, and not to derail the thread into a workflow debate, explorer (particularly in W7), is a hugely underrated workflow tool. Easy to sort and group pics, based on many more attributes that are available by default. Right click on a column, click "more" and voila. Not sure how many of those are options to LR or anything else. I don't use them, because I want to own my own workflow. I write my own scripts and such to handle all that in an editor-agnostic way, I don't use the "library" concept. I realize that one day, I'll probably succumb to it, but I'll hang as long as I can.