The independent technical assessments of the US decision to shoot down the failed US spy satellite are starting to become public. Here's a link from the IEEE:
http://spectrum.ieee.org/aug08/6533
While it's a great example of risk assessment and technical achievement it also shows what a exceedingly difficult task it would be to have a automatic ABM system. The article also describes some misbeliefs about meteorites. I'll leave the opinion about the political decision to shoot it down to others.