Big, big spoilers for Roy in this show - don't read it if you don't want to know
Colton gave an interview and said Roy gets superpowers...
Here's how I think it'll play out:
Blood injects Roy with the MIRAKURU and it gives him super strength and super healing or whatever. BUT, he has to keep regularly getting the drug from Blood in order to keep his powers and it'll be a twist on that whole Roy Harper drug addict/MYWARDISAJUNKIE story.
Seems like time will stop for the Arrow crew, The Clock King is coming
http://tvline.com/2013/12/11/arrow-cast-robert-knepper-clock-king-william-tockman/
Robert Knepper (from Prison Break) shall play him
i'm so ready.