As far as not announcing TESV while FONV is in the tail-end of its pre-release marketing cycle, consider this: one of the most important (and time consuming) jobs that a company has to do is cover its rear. As its stands Bethesda is the rights-holder for Fallout, BGS developed the last game in the series, and now BSW has arranged to have Obsidian develop a follow-up, FONV. BSW will publish, promote and distribute FONV, and retain the rights to the property. People buy the game, and BSW and Obsidian get paid. That is the situation.
This is how the business works, in order to bankroll the development of a game, the publisher puts up some cash and assumes risk. Upon release, sales first pay back the money the publisher put in to fund the development and marketing, and further profits get carved up between profit for the publisher and bonuses for the developers. The bonuses are based on target sales figures agreed to in the deal between publisher and developer, and are generally considered private information (the specifics of these deals are rarely made public).
Now if FONV doesn't sell well -- for whatever reason -- and falls below agreed upon sales figures, the publisher (Beth) will not have to pay the developer (Obsidian) as much money in terms of scale or bonuses, and meanwhile -IF- Bethesda has been talking up TESV, Obsidian (or its share holders) could POTENTIALLY go crying to a judge and say that the publisher failed to promote the game fairly, and other junk, and it MIGHT become yet another messy lawsuit in the industry - it seems like a new lawsuit pops up monthly as it is.
NOW IT IS VERY UNLIKELY to ever play out like that, BUT the first rule in business is to CYA, and for that reason, among others, Bethesda has little to gain, and more to risk by announcing a game like TESV while it is handling the marketing and release of another major release. And when it comes to CYA, it is not the FACT that TESV could steal some of FONV's thunder, it is the PERCEPTION that matters.
I mean, people are looking forward to FONV, but you gotta admit, its not being called Fallout 4 for a reason. It is a weird situation where it seems like more of a really large expansion to Falllout 3; Fallout 3.5 maybe. The small percentage of the gaming public who knows that Obsidian employ some former Black Isle people who worked on the original Fallout games want to see what they will do with the engine and assets that Bethesda created when they changed their game from a turn based isometric game into a first person action-RPG, but the great majority of game shoppers don't have a clue about any of that. We have every reason to believe that TESV is going to be a major step forward, so it is quite likely that starting to talk and show assets from TESV will make FONV look even more like FO3.5 by comparison.
Compared to the potential failure to CYA as a publisher of the next "Oblivion with guns" game for another developer, and their desire not to have another RAI incident, as well as their stated intent to have the shortest time between announcement and release yet for their next game, what would Bethesda have to GAIN from announcing TESV before the end of the year?
Also, look at Id, around Quakecon they said that they're not talking about Doom 4 because they're promoting Rage -- another example of a game company focusing attention on one product that is closer to release and keeping the next game in the pipeline out of the spotlight.
Exactly, someone else that knows marketing besides my self.
Let's go all the way back to last year at quake con, Todd said last year don't look for a game anytime soon. Most people don't realize that he was speaking in game terms. Generally speaking most games of the blockbuster games have a production cycle of 36 months. Todd already confirmed to us that the game was in pre-production while they were making Fallout 3. So effectively he is saying one year of pre-production and a simultaneous development of the engine and game it's self within the next 24 months when they ramped it up to full production. They probably tailored off redoing the engine within the first 12 months of actual production and now have both teams working on just the game it’s self with a skeleton crew to tackle bugs that crop up. A next Elder Scrolls announcement would be huge, so huge that it would force other companies to push around there titles to make way for it. It is the game that everybody dearly loves and wants to play. I doubt it’s going to be an online title because they already have Fallout Online which is being promoted by Bethesda and Obsidian (mainly Obsidian).