I can think of a thousand instances where I could use 15 extra points in the build I have made. More importantly though, it means I can finally get Mass Grave and something else from another soul tree. Or atleast go high Necro and get Burn so I get those melee off of me. I think we're going to be seeing a lot more specs with 15 Ele in it for the crit damage boost however.

How does 15 points affect your specs?

EDIT: Yes, I forgot an of between a lot and fun. pity I can't edit me title either.