A new Elder Scrolls will probably be made. But I doubt it will be any time soon. Definitely not before a new Fallout (or something else) comes out first.
Elder Scrolls and Fallout games are very, very ambitious games.
The time it takes for Bioware to produce 4-5 games is the time it takes Bethesda to produce a new Elder Scrolls or Fallout.
Just to give you an idea, Elder Scrolls Daggerfall is arguably the largest RPG ever. It covers an area of half the United Kingdom.
Now whilst subsequent Elder Scrolls games haven't been quite as large (it is difficult to be that big and still be graphically up to date), they still cover massive areas.
Not only that but you have a lot to program: NPC's, quests, abilities, perk trees, character progression, storylines, dungeon design, lore, enemies, encounters etc.
There is so much that goes into an Elder Scrolls and Fallout game.
Either Bethesda takes the time to get it done right, or they simply don't bother making the game.
So another consideration is do the Bethesda team feel they have the inspiration to craft an Elder Scrolls game on par with the 5 magnificent previous entries?
If the answer to that question is no, then it is possible that the next game may not come out, EVER!
I hope that is not the case, though I'd rather the last ever Elder Scrolls was a fantastic entry like Skyrim than the last in a slew of rushed poorly crafted titles.