Just a couple of thoughts, too.
In the "WAY" scene, as they are preparing for the spell, when Willow was pulling the curtains closed to the dorm room, did anyone notice the look on her face? It was a bit like, "Okay, here we go. I'm taking the Nestea plunge now!" Metaphorically speaking (cuz we're not talking about sex), it's like when two people acknowledge their love for each other and then take the next step towards consummating that love. This seems like a scene in which Willow fully understand the depth of this without reserve albeit, nervous as hell. Tara was bitten by the bug early on...I think if Willow were 'out' as Tara was, she may have acknowledged her attraction for Tara much sooner, but being inexperienced in girl's town, she didn't know what to make of her new found feelings for Tara.
Again, just some random thinking patterns here.
Stopping now.
And I think for Willow that was her equivalent of Tara's earlier "yours" statement. I think at this point they both knew it was big and it was mutual and it was love. 