Credit goes to Gubie here : http://social.technet.microsoft.com/...6-241487d65303
It's for the Slate, but the driver is by ST Electronics and it's the same chip manufacturer for the Duo.
I just downloaded and installed the (32bit) driver on my Dell Inspiron Duo. Rebooted and it works GREAT! Didn't even unzip, installed straight from the ZIP file.
Metro desktop rotated. Launched Metro Kindle and it came up rotated.
I thought I should share. I get such great info here.