What can you do on oblivion the elder scrolls vi

elder scrolls vi hasn't even come out yet, but iv (oblivion) you can just about do anything, like ride horses, create your own race, pick locks, join four guilds(assassin's, thieves, fighters, and mages), you can steal, explore dungeons, murder people, quest for powerful weapons, use magic, fight in the arena, use speech to your advantage, and much, much more.

The elder scrolls VI will probably be Valenwood, the homeland of Bosmers.
In the meantime we can explore Skyrim more, and start playing the Elder Scrolls Online as it comes in 2013. That may postpone the release of TES VI.

Most probably TES VI will be released before 2018.