Warning--old guy rant:
I know I sound like a broken record, but I'll say that we'll probably see the Fallout 4 reveal at E3 with the game being released 4th quarter 2014. That'll put the release of TES VI sometime in 2016. And this isn't personal on the part of Bethesda, and not some kind of slap in the face. It's just the end of the natural development cycle. They gave new content to this game for almost a year and a half after the launch of the core game. The only other company I know of that does this, and it's a company that lots of people like to throw under the bus, is Capcom. They've been actively supporting their Street Fighter IV series since 2008.
Anyway, Fallout 4 is going to be great. Bethesda is going to do all kinds of new things with the Creation engine. Remember the visual leap between Oblivion and Fallout 3? We're probably going to see that sort of thing again. And with a TES title 4 years away, Bethesda will likely take what they learn from the new Fallout and apply it to a new engine for TES VI. And that is the important thing to remember going forward, especially for you newer guys that came into the series with Skyrim. TES and Fallout are reciprocal titles; they feed off each other. Fallout, since it was acquired by Bethesda, has essentially become Elder Scrolls with guns. If you aren't interested in the title, then don't play the game, but it is still worth paying close attention to it, as it will be a sign of the direction of the next TES title.
In any case, do not fret. It's all just the beginning of the next cycle. And the mods will keep coming out for years. After all, we still see a very active Oblivion modding community, and that was a 2006 release. Skyrim fans will have many adventures yet to come.