The 24-year-old winger failed to find his niche in New Jersey, and never really established himself as an NHL player, so it's no surprise to see him head back home.
In Sweden Tedenby will be closer to friends and family, get more ice time and likely signed a more lucrative deal than he'd get here, so this move makes sense for him.
I believe the Devils retain his rights should he ever come back to North America, but I wouldn't bet on it.