Matthew Holt is quite enamored with Uwe Reinhardt's discussion of HSA's at a recent KFF event. Matt pasted the transcript over at THCB, but the gist is that using HSA's as a way of controlling costs actually shifts the responsibility of cutting back on health services principally on the backs of the lower third of the U.S. income bracket. It's well put and worth reading if you have a few minutes.
Uwe Reinhardt also spoke at the National Health Policy Conference in February. He's a fantastic, engaging speaker. I don't think I've ever seen someone able to make health policy so funny. Any Democratic candidate with health reform on the brain would be genius to just bring him along on campaign stops to go after HSA's. He's damn convincing.