Well, to stop worrying about whether my comp will be able to run Skyrim on high graphics or not...
I'll probably give Oblivion one last playthrough.
(However, it's very possible I'll return to it sooner or later anyway.)
Also, I turn 18 not long after Skyrim is released, and I'll probably stop gaming not long after.
I'm happy that it's Elder Scrolls V which will be my last PC game. It seems fitting.