Besides higher costs imposed on corporations and employers, there's the additional $115 billion implementation costs that the CBO admits it didn't include in its original projections because they "didn't have enough time to accurately estimate health bill's cost", plus costs for "high risk pools", for early retirees, and for the Medicare "doc fix".
(Read the full text of "ObamaCare's Hidden Costs".)
With respect to the $115 billion extra cost reported by the CBO, there are many liberals claiming that these are all "discretionary".
But as Megan McArdle notes in "The Health Care Reform Already Costs More Than We Thought It Would":
Some of the stuff we do have to fund, because the agencies are going to have to have staff to deal with the new requirements; and the stuff we don't have to fund is the demonstration projects that I was assured were going to bend the cost curve. So if we save this money in the first ten years, we lose the possibility of lower cost growth after the first decade.I suspect we'll be in for more unhappy surprises in the near future.
What's really worrisome, however, is that I'm unaware of any happy surprises where it turns out this thing is going to cost less than expected.