I'm cautiously pessimistic about Oblivion. The last one in the series, Morrowind, the previous Best Thing Ever, was an ugly and buggy piece of shit; it was also boring. The one before that, Daggerfall, was also an ugly and buggy piece of shit.
Besides the random bugginess/shittiness, the real problem with those games, from my point of view, is that they were essentially plot-free sandbox games. I find those kind of games boring... there's so much to do, that there's nothing to do. Basically Morrowind had the plot and NPC depth of an MMORPG, without the other players to interact with.
That said, the screen shots are nice, and it sounds like they've tightened things up in this iteration. Maybe the third time's a charm.