Gameguide? Nah, never cared too much for them. I own the Skyrim one, but that's only because GameStop gave them away for free to everyone who bought the game.
If I'm offered a free guide, then sure, I'll take it. But I won't pay for a gameguide, besides if I get really desperate I am sure wakthroughs will be up and running reasonably soon. But I haven't used a walkthrough in a long time.
After I complete the game the first time, THEN I might pick up a guide to see how I might do it differently (if I have no clue what I want to do differently) and to pick up what I missed. I tend not to be able to get all the bobble dolls the first time around, nor all the locations that are available because I'm so excited! But I take my sweet ass time the second time around.
Ive never really been stuck in a Beth game, but i have had quests bug out in ways that I would need the knowledge gleaned from the GECK to resolve.
So meh. Strategy guides aren't of much use for me, but I can see why people want having all of that info on hand. Its just how people personally play the game, and I agree that "Just use the wiki!" isn't a good substitute in the early days.
Getting guide on release.. always do with big exploration type games. I don't use it to spoil the story/plot but I do extensively use the maps and area descriptions in the back. There's always info in Bethesda games that you do not learn about within the game itself that's in the guide. Example: FNV - Yangtze Memorial... There's nothing in game that tells you what this memorial is. If it weren't for the location popup that tells you it's the Yangtze Memorial, you wouldn't even have a clue as to it's name. No plaque to read or anything. The guide gives you a run down of what it is and who it was built for.
Ehhh I don't think game guides are worth my money. Plus I like figuring things out on my own.
If it's as well written as past BGS guides, I may buy it just to keep in the bathroom. Morrowind and Oblivions guide were actually pretty funny reads. Whoever it was that wrote the details had a lot of sass, and it read more like a good Let's Play than a walkthrough guide.
Other than that...I have the internet, and my first playthrough will be blind as a bat with the occasional internet searching for specific things.