Sheldon's got the deets later, but we've got them now.
http://www.nintendoworldreport.com/news/41532/splatoon-update-prepare-to-be-bamboozled-once-more
The Splatoon update train will keep rolling tonight US time with the Bamboozler 14 Mk II.
A modified version of the Bamboozler appears to be firing at a longer range than the standard version, and has a slightly different physical appearance. It packs a Disruptor for a subweapon and a Echolocator special.
The update will come at the usual time: 10 p.m. Eastern time / 7 p.m. Pacific tonight.