The towering goaltender was recently pushed to No.3 in AHL Norfolk when the Lightning signed Jaroslav Janus  from Erie of the OHL. Dustin Tokarski  is the No.1 in Norfolk, though he's currently filling in for an injured Mike Smith  in Tampa.
Helenius will join Sodertalje SK of the Swedish Elitserien League, and according to his agent, Jay Grossman (via Aftonbladet), this will give the young netminder more playing time.
Helenius was drafted in the first round (15th overall) at the 2006 NHL Entry Draft. He appeared in 12 games for Norfolk this year, posting a 5-7 record with a 2.75 GAA and .896 save percentage. He appeared in one game for the Lightning last season, stopping both shots he faced in mop-up duty. He previously played for Seattle of the WHL.
Update: The Lightning have confirmed the transaction, along with Tokarski being reassigned to Norfolk (1/24).