Here is my suggestion. It is a bit of an overhaul, but it would be what I would do to make Bear a good tank (without making them simply the best).
Ursine Adept allows all druid instant cast spells to be cast in bear form.
Mastery health and healing received doubled.
Spec Tree:
-Connections added:
=Killer Instinct to Feline Swiftness
=Sunfire to Remove Corruption
=Nuturing Instinct to Astral Influence
-Maim usable in bear form for 20 rage.
-Matted Fur reduces your Barkskin cooldown by 10 sec.
-Well-Honed Instincts 1 pt talent for “up to once every 90 sec.”
-Ursine Vigor added “and you retain your armor for 2 sec after leaving Bear Form.”
-Renewal reduced to a 30 sec cooldown.
-Heart of the Wild changed to 20% improved, active at all times.
Bear Tree:
-Survival Instinct upped to 2 charges, Improved Survival Instincts removed.
-Brambles doubled in value, reflects magic damage as a mini block.
-Beserk:Ravage becomes Beserk, all three nodes rolled into that node.
-All talents in row 5 dropped to 1pters for the same benefit.
-Layered Mane up to 25% chance for both effects to occur.
-Rend and Tear choice node moved to where Beserk:Unchecked Aggression used to be.
-Lunar Beam moved to where Beserk:Persistence used to be.
-Lunar Beam increased by 400% and cooldown reduced to 45 sec.
-Tooth and Claw and Pulverize apply buff to the druid, not the targets.
-Ursoc’s Fury increased to 50%.
-Dream of Cenarius cannot occur more than once every 10 sec.
-Ursoc’s Guidance changed to 10 Rage for 1 sec off Incarn and Surv Instincts.
-Twin Moonfire changed to Moonsfury: “Moonfire debuff hits every target with your Thrash applied to it.”
-Thorns of Iron increases in damage up to 5 targets before splitting.