Found a new Japanese dictionary program today. It's called DiDi Dictionary. It's a universal binary, understands the PDIC format that Eijiro comes in and was really easy to set up. I spent a few hours cobbling together a cocktail of Quicksilver and GUI scripting to give me a near-universal lookup function with just a tap of a function key. I can't believe how long it took for me to work out how to tell my script what the current application was.
DiDi Dictionary is currently free and is still in beta. The program and the site is all in Japanese but if you're looking for an Eijiro capable dictionary you probably have enough Japanese to work it out.