GNOME != Fedora

Sometimes you need to use the final version of something before you see why it is handy. E.g. smartphones. They've been calling various phones smartphones, while the only thing they could do is e.g. bluetooth and a calendar. Now loads of people cannot live without them.

I expect semanic desktop to be similar. Added value atm is low (it seems, don't use KDE), in future: everything it provides would be considered normal by the users and if you don't have it your phone/pc is just ancient.