An interesting take on the decision:
http://www.foreignpolicy.com/articles/2009/09/17/the_new_defense_realism
I oppose the decision exclusively on the basis of the signal it sends, and do agree that it probably makes sense in terms of countering the actual threat. I think FP unreasonably dismisses the damage done to our relationship with Eastern European countries. We're going to have to move quickly and decisively to repair that damage.