Now that the 50 state commemorative quarters are almost done (2008 will give us OK, NM, AZ, Alaska and Hawaii) the US Mint is jumping right on the tail of that success with the $1 Presidential commemorative coins. Washington and John Adams are already minted, Jefferson and Madison will round out 2007. The official release schedule goes through 2016, with Nixon and Ford, but does not include Reagan. I'm sure it will - the mint is not allowed to print the image of a living person on currency, and I expect the list was drawn up while Ronny was still above ground. Cleveland gets two coins, thanks to serving two non-consecutive terms.
I've subscribed to the Quarters series, and just put in for the Presidents series, and was poking around for other items of interest (there have, for example, been some interesting nickels showing up in my change). Are you sitting down? Good. Because there's one more set coming:
The First Spouse Gold Coin Program
I kid you not. Follow the link and you will find Martha, Abigail and Dolley on a $10 gold coin. Jefferson was not married, but instead of putting Sally Hemmings on a coin, they punted and put Liberty on his. Jackson, Van Buren and Buchanan get the same treatment. Tyler's two wives will share one coin, as will Wilson's. Like her hubby, Frances Cleveland gets two coins.