i think kol will be killed, because in next episode they are going to find the cure...
Hahahaha is this raelly necessary?! Anyway,lemme try answering you! I dont think he'll be killed off...cause I refuse to believe that Klaus and by extent Rebekah would let tehir own brother be killed off..though they may not know Elena's plan...but I think Kol will be daggered or desiccated by Bonnie (Jeremy asks for Bonnie's help)..then Elena takes the white oak stake and hands it over to Rebekah the following episode (Into The Wild) and perhaps Kol will be revived when Elijah comes to town in 'Bring It On'
I'm betting on daggered. Kol has a much heavier role than Finn in a lot of ways. So I doubt they'll "seal" his future scenes in TVD ^^ he's just really afraid of Sylas. Which we will be knowing why~ perhaps then we'll have some kinda "plot-explosion"
It's sad. I think that he will die. I next week's episode they are on an island trying to locate the cure. In order to do so, Bonnie must survive tonight's episode and Jeremy must complete his mark. The quickest way to do that is to kill Kol. Plus we know that somebody will die in tonight's episode. 
There's still a tiny bit of hope Kol will still be kicking after 4x12, but I think everything is pointing to Kol being killed--
Elena having the stake in the next episode. Jeremy's mark being complete. Another reason Rebekah will be angry at Elena, as we've seen through some promo pics. Damon's compulsion being lifted (although that could be daggered..)
I think Bonnie will desiccate him, or something along those lines and Jeremy will stake him- assuming Kol takes the stake with him everywhere. Elena will give Rebekah the stake in the next episode as an attempted peace offering after killing her brother.
Im just about getting over my anger about why they even introduced him & the family in the first place if the main three; Klaus, Rebekah and Elijah are the only surviving Originals.
What do you think?