The girl's/Master Sword's/Fairy Queen's attitude

Well, this "attitude" personality like Tetra and Midna does really work when it comes to making a character loved... I mean, how many liked Saria or Ilia that much?
Flirty you say, in that case I hope she'll be like Telma the bar lady in TP.

I don't believe she IS the master sword, rather a spirit that makes it more powerful. Like the wind god in Gales Boomerang in TP. That doesn't however explain why Link holds no sword, but that might just have been made as a hint.