Although the cause of the Continental Flight 3407 in Buffalo the other night is unknown, there's been discussion that tailplane icing is involved. This is a great video from NASA that explains the effects of tailplane icing.
The whole video can be found on Google Video
Or it can be found on youtube in 3 parts:
This is not meant as speculation - we must wait for the final NTSB report to determine what really happened. Regardless, this is a very informative video for all pilots.
My thoughts are with all those affected by the accident.