All forms of media influence all other forms of media, this is a pure fact of human existence. Nothing has been original since forever, yet that doesn't mean that the learning process is entirely one-sided.

Bioware did far, far more than merely take inspiration away from WoW, there are loads of abilities that are literal copies. Not that every WoW ability is a unique snowflake that never existed before, but I feel the Telekinetics and Lightning trees are the most telling. They have an exact replica of the Elemental Overload talent, of Elemental Focus, and of Lava Burst. From there, they have extremely similar abilities too -- Thunderstorm is copied, Earthquake is copied, and so on.

And it's more than Elemental. The talent Kinetic Collapse is a duplicate of Arcane's Incanter's Absorption. Mental Alacrity is a copy of Icy Veins. That's just for a single spec. Bioware took a lot from Blizzard's current talent and class design in the way that they built their classes, and why shouldn't they? WoW has amazing class balance, especially when you consider how many variables there are to balance around. When there's so much "inspiration" going on, it's a bit telling when nothing from your spec makes the cut.