While we are waiting for the details from Cash for Caulkers to come out, there is nothing holding you back from improving your home. The general principal is nothing more then what is being preached in the Go Green movement and the great news is this movement is all about helping people see how or why the appliance with the cheapest upfront cost is not always the one that saves you the most money even after a couple of years.
Cash for Caulkers also goes by the name HOMESTAR (sometimes HOME STAR with the space) but fundamentally this program is a tax incentive program tied to the GO GREEN campaign of educating consumers about how they can save money and the environment at the same time. The great news is you can start projects following the Go Green model now. While it is unclear what will be in the final tax incentive, anything you do that is oriented to Going green will leave you with more money in your pocket anyway.