I like the idea and have allowed it to work from the start.
I see worries about "Next turn" effects simply being different from "Save ends" effects (as opposed to being strictly inferior). But before 4E was released, there was an article about the new "Save ends" mechanic.
In 3.5, multi-round effects (and power recharge) had their duration determined by a low-dice roll. That had two disadvantages:
1- Failure to count turns properly. Ask any player or DM; sometimes, we just miss a turn or two.
2- A fixed, fatalist duration. A player can go do something else once stunned, knowing fully well when to come back.
The article introduced "Save ends" (and power recharge) as a new way to have effects last multiple rounds. By rolling each round at a fixed time, we seldom forget about the effects and can't know in advance when they will end.
I figure "Save ends" are intended to be strictly better than "Next turn". Why would hobgoblins not be able to try shaking off those weaker effects?
Unfortunately, the time at which effects end varies. Some last a whole turn while others can very well end on the next initiative count.
Some effects affect a creature only on its turn (penalty to attacks) while others are, instead, beneficial to others (penalty to defenses). In isolated cases, a power can impose "Save ends" on a hit and "Next turn" on a miss, which can lead to unbalanced results.
Still, in my opinion, the occasional superiority of "Next turn" is a by-product of the duration simplifications. I definitely allow out-of-turn grant-a-save powers to work against "Next turn" effects.
One could even try to change the "Save ends" time to the effect issuer's turn... but I don't want to.