Yes, you get some normal slayer points with duoing, but only about half what you would if you solo'd (seems to vary based on who got more kills between the two of you). Only the block list of the person who actually gets the task is used, and you can get a task without both people being present. You can't get a task from a slayer master that either of you can't use due to low slayer or combat levels (and it just tells you that, it doesn't assign a solo task). If you wander too far away from your partner, or if one of you leaves to bank or the like, the kills you make won't count towards your parter's task total, and vice versa - thus it's entirely possible for one person to finish a co-op task before the other.

 

And I gotta say that duo-cannoning banshees and hellhounds is freaking awesome. Especially with one person d-claw-speccing and the other ice bursting.

Soon as I noticed the bar in my browser window I switched to client. I'd rather have the ads.

 

The Gielinor Games should be fun, but once again it's an update of Varrock Square wherein my FPS drops dramatically when I'm within the vicinity. Had to switch to low-res fixed-width just to do the tasks. I think I need a shortcut to the GE. Ja-joy. Ah well. It's the Olympics! But with... gnomes! I'm game!