Just looking for clarification on the Thunderbolt Display....can I use it (and none of the other features) only as an external display on a 2010 iMac that doesn't have Thunderbolt? I don't have a need to play sound, use the iSight, ethernet, or anything else off of it. Just the external display part. As I understand it...I can only plug in the iMac to the Apple Cinema Display, and I could use the TBD on my Macbook Pro. Thanks.