The current count on what states are doing on Obamacare, the financial consequences

I think that the Kaiser Family Foundation is counting DC as a state.  From The Hill newspaper:

As of May 10, according to the Kaiser Family Foundation, 17 states will run their own exchange, seven will partner with the federal government and 27 will default to a federally run exchanges. 

Another 29 support the Medicaid expansion, while two are weighing their options. The rest will not accept the expansion. . . .

A thought: I can't image that states really believe that they can count on the Federal government to keep picking up the costs of the Medicaid expansion.  Four or five years down the road when the budget deficit is getting worse, there will be real pressure to cut spending and this will be a prime target.  If the number of states supporting the expansion stays below 30, it could make a big difference for what happens financially since 21 states have a total of 42 Senators, enough to maintain a filibuster.