My copy-pasted 2 cents:
"There are two games here. One is a Fallout game. As a Fallout game, Fallout 3 sucks. Plain and simple.
The other is a post-apocalyptic Bethesda game. Remember that "We’re not going to suddenly do a top-down isometric Baldur’s Gate-style game, because that’s not what we do well." quote? That sums up FO3 well. They did what they do well.
From that perspective, the game is definitely an improvement. Lotsa skill checks (hopefully the next TES game would feature them as well). Multiple objectives. Non-linear main quest (for now). Exclusive content (for now). Different quest options (again, for now). If "for now" turns into "overall", I would be pleasant surprised and impressed.
Dialogues are bad. Really bad. Stat lines are absolutely idiotic so far. Looks like whoever wrote it had no idea what a smart or charismatic person is supposed to say in certain situations.
VATS is poorly designed. The slow motion thing is annoying. I use VATS to "get it over with" because the alternative is a clickfest.
Hacking minigame is boring. They should have made it skill-based. Lockpicking is "meh", but at least the skill check prevents trying till you get it right.
So, forgetting about Fallout and talking about the new Bethesda game, unlike Oblivion which was bad, Fallout 3 is flawed, but shows promise. After the modders are done with it (hopefully rewriting dialogues, changing vault 101, VATS and hacking), it could be a pretty good game."
Updated:
"At the moment, based on my current impressions (!), it looks like it's a pretty good game overall. Again, keep in mind that I'm still at the early stages of the game.
The fact that it was supposed to be a Fallout game constantly gets in the way and requires a mental block to ignore. It's hard not to compare the game to Fallout and develop a negative impression because everything is inferior (character system, quests, characters, dialogues, combat, etc). That's on one hand.
On the other hand, comparing FO3 to, say, beloved by many Gothic results in a favorable impression. While Gothic is incredibly atmospheric and allows you to side with whoever you want, the character system is simple and often broken, dialogue options are practically non-existent, translated German leaves much to be desired, combat is flawed, and you won't find any depth in quests.
So, the real, unbiased question here is - how does Bethesda PA game compare to similar games not to venerable and completely different Fallout? Comparing it to Fallout is like comparing it to PST. Predictable and serves no purpose other than bitching about Bethesda unwillingness and inability to do "what they don't do well". "