Yes, the 2 DVDs are exactly the same from what I can see. The update from 2005 to 2008 only effects the actual application CD.

Is it worth upgrading to the 2008 edition? Not sure. It depends on what you want to use it for. The Linux based Amiga emulator is a great new addition. Similar in idea to X-Amiga (same developer) and AROS. The main WinUAE based emulation is obviously updated to a newer version of the emulator, and some additional things have been added like a quick launch program to load games and demos. Quite a basic frontend for WinUAE, and I found that didn't work too well.