While it would be nice to link up with friends, I guess mods that do more than change user interface are not possible. One of the things I love about ES is the ability to change whatever aspects of the game world suit my whims via mods.
There is much wisdom for me in SubRosa's sentiment about an SP version. To me the biggest draw of ES(O) would be the ability to explore all of Tamriel - and an on line game is not needed for that.
One can only hope that, in the future, the answer to 'Where will the next SP TES game take place?' will be 'All of Tamriel.' I don't mind one bit if travel between provinces is simply crossing borders (like the Elsweyr and Valenwood mods do in Oblivion) or if each province is its own world space (like Oblivion did with Shivering Isles and Skyrim did with Solstheim).
Anyway, I continue to be curious about how ESO is doing.