Ezra Klein settles the argument at the health care summit as to whether costs would go down after reform:

Lamar Alexander and Barack Obama just had a contentious exchange on
this point, so it's worth settling the issue: Yes, the CBO found
health-care reform would reduce premiums. The issue gets confused
because it also found that access to subsidies would
encourage people to buy more comprehensive insurance, which would mean
that the value of their insurance would be higher after reform than
before it. But that's not the same as insurance becoming more
expensive: The fact that I could buy a nicer car after getting a better
job suggests that cars are becoming pricier. The bottom line is that if
you're comparing two plans that are exactly the same, costs go down
after reform.