I recorded 1080p with the camera to my sd card from my og droid, a 16gb class 6. I used astro to verify it had saved to the sd card that I had installed.
Interestingly, it lists the internal media space as "sd card" and the card that I installed as "sd cardext".
So long as I can put my apps on the "internal sdcard" then I am fine, but on the Droid Charge there was enough lag with the apps on the sdcard that I was not happy with it and you only got 1.11GB from them.