Improved Mark of the Wild is a talent in the first tier of the DruidRestoration tree. In addition to greatly increasing the effect of the [Mark of the Wild] and [Gift of the Wild] spells, it also increases the druid's total strength, agility, stamina, intellect, and spirit by 1%/2%. Note that while the bonus to Mark of the Wild applies to everyone affected by the druid's Mark of the Wild, the passive increase to attributes only applies to the druid herself.
At level 80, this talent will increase the bonus from Mark of the Wild by 300 armor, 15 to all stats, and 22 to all resistances. This applies to all party or raid members affected by Mark of the Wild.
As the passive bonus affects all attributes, this talent is useful for druids of all specs. Feral druids will gain strength, agility and stamina while Balance and Restoration druids will gain stamina, intellect and spirit.
The value of the passive part of the talent increases as the druid gets access to better gear. This to some degree mitigates the fact that the attribute bonus from Mark of the Wild gets less noticeable as the gear level of the group or raid improves, ensuring that this talent is always useful.
Tips and tactics
If there is more than one druid in a group and one of them has this talent, the druid who has Improved Mark of the Wild should do the buffing as all party members will benefit from this talent.