How could we possibly know this? If you're very concerned with your first impression of Fallout 4 your best bet is to cancel your pre order. Wait half a year and buy it after it has been patched several times.

I reckon it'll be at least as playable as Skyrim, probably better. I wouldn't let my initial impression affect me too much since we know that patches and mods will eventually iron out most bugs. For me, the long term impression is definitely more important. The potential of it. I've started seeing newly released games as a base from which to build. Give it a year or so and it'll be awesome once loaded up with mods =)

I seem to recall Skyrim having a day one patch..

I don't remember with Oblivion or Morrowind..

I imagine very playable for the majority of people. I'd hope any bugs left in get patched quickly, and no quests are broken. Really the only problem i had with skyrim was with the quest blood on the ice, i still can't finish that quest to this day. Beyond that i've never encountered any bugs that hurt my enjoyment of the game

This.

And the one undeniably nice thing about DLC other than the new content, is it means there is a dedicated team working on the DLC AND on patching the game.

After all buggy games don't sell much DLC.

Bug fixing goes from being an expense with a rather limited budget to being part of a major source of revenue.

And my understanding is that nearly the whole Fallout 4 development team will be working on the F4 DLC once the game is released.

It will be fine. I keep hearing that Bethesda games are super buggy, but I just haven't seen it. Yeah the physics occasionally glitch out, and there were a few minor quests in Skyrim that locked out, but nothing that was particularly egregious. Nothing even close to "broken."