Are you going to update Epson Smart Panel to work with Yosemite OSX?
There is no information about the release of the Epson Smart Panel for Yosemite 10.10, but according to an official statement, most of the Epson drivers and software are updated through the Apple Update.
You can check the statement at the following address: http://www.epson.co.uk/gb/en/viewcon/corporatesite/products/mainunits/faq/12304/7716
You will need to use the Apple's built-in Update feature to look for updates for this application.