You can find Judge Vinson's opinion here. I have just skimmed the 65 pages, but this appears to be the bottom line (on the merits):
1. The minimum coverage requirement is not a bona fide tax, but instead a regulation with an accompanying sanction. As such, if it is within Congress's enumerated powers, it must be justified as a regulation of interstate commerce.
2. The states' claim that the minimum coverage provision exceeds Congress's commerce power is plausible, and thus survives the United States's motion to dismiss. Whether the claim should ultimately prevail will be determined on the coming motions for summary judgment.
3. The states' claim that the ACA's Medicaid amendments are coercive, and thus effectively commandeer the states to implement a federal program, is also plausible, and thus survives the motion to dismiss. It, too, will be resolved on the coming motions for summary judgment.
4. Because the minimum coverage provision is not a tax, the states' contention that it amounts to an unconstitutional, unapportioned "direct" tax is moot, and thus dismissed.
5. All of the states' remaining claims--that the minimum coverage provision violates the Due Process Clause of the Fifth Amendment, that the employer mandates amount to an impermissible burden on the states, and that the provisions implementing the so-called "exchanges" impermissably infringe on the states' independent sovereignty--are all dismissed for the failure to state a claim. They are all implausible on the merits.
I am sure there is plenty more in the 65 pages. But this is the basic gist. I will try to offer some more analysis once I have a chance to wade through the opinion.