There is one for Windows 8.1, but apparently not for Windows 8.1 Update 1, so I guess MS hasn’t publishing one this year after Update 1 was released, or maybe Update 1 includes support natively if you have Pro. I have no idea:
http://www.microsoft.com/en-us/download/details.aspx?id=40310
I have Windows 8.1 Update 1 with the Pro Pack and a Canon 450D/XSi from around the time the 7D came out and I can import raw photos from it ok in LR. I rarely do this and almost always use Explorer to copy the files to my hard-drive and then do an Add Import from there.