If we want "powers per beast", we should probably provide them in an essentials-like way.
The idea would be that the Ranger could pick a beast power instead of a Ranger encounter power at a given level, and it would scale somehow.
Rituals/Martial practices attached to a beast form would also help.
Bear + Primal Defender
Mighty Bear protects her cubs.
Based off Brawler Fighter. Its attacks mark. Has Grabs, taunts, etc.
Challenging Roar + Blast 5 vs will, enemies pulled and attacked.
Savage Claws + Daily aura 1, deals [ B ] to adjacent foes.
Bear Hug + Attacks 3 small, 2 medium or 1 large or greater foe, vs Fortitude. Grapples.
Wolf + Primal Striker
Savage Wolf brings the pack's foes down.
Hunting Howl + Tag foes as prey. Get a damage bonus on first attack on each.
Pack Tactics + Knock a foe adjacent to an ally prone, repeat whenever they try to get up.
Go for the Throat + Damaging attack with larger crit range. If the foe is under certain HP the foe dies. Has a chance to recharge if the foe isn't killed.
Eagle + Primal Leader
Majestic Eagle leads, if you will follow.
Overwatch + Creates a zone where allies can make OAs on foes.
Bannerbird + Lands on an allies shoulder, creates an aura around them.
Distracting Swoop + Immediate action, makes a foe miss / gives ally an attack against them.
Coyote + Primal Controller
Trickster Coyote messes with your enemies plans.