Things got quite close by now: mandatory driver signing in 64bit Windows Vista & 7. You need to select extra boot option to be able to load unsigned driver. Like the venerable ext2fsd: driver for ext2 & ext3 FS [1]. It won't work for Joe the Average User.
Terrorists win, game over.
EDIT:
it's a clever move, limititing that requirement only to 64bit Windows. No need for one-time big switchover; the balance towards 64bit will shift gradually over time and before people raise enough opposition it may be too late for independet driver development.
We already know security based on centralized Certification Authorities did not work well for securing HTTPS.