So brought a disciple and blood Mage to ten for the rewards, started a sorcerer, but abandoned him and now am back on Delat working my way towards the cornerstone of awesomeness for the shaman.
Level 15 for a shaman is where you pick what type of play style you want, and makes you incredibly more effective at dealing delicious death to all you see. There are three choices: a caster focus, tankie focus, and a mix.
When you're picking, you are choosing your patron. Whichever you pick will give you a new buff, some abilities, a pet and the ability to shape-shift into the form of your patron. Caster is a bird, tank is a bear, mix is a wolf. Delat will go wolf. You get a melee buff, wolf form buffs damage and regen, makes you run faster the a horse at that level, and some melee abilities. Once a shaman hits 15, life improves significantly.
Got 14 tonight, so I should have delicious awesomeness tomorrow. I cannot wait.