(1)
Of course it's not free.

(2)
MHL is a protocol (no phy layer), charging is not a requirement of the spec.
Just a feature if you happen to be using mUSB as the medium.

It's not HDMI, stop calling it that! LOL
I've already said it's unlikely (albeit not 100% impossible) & explained why, no false hope here!

If Nokia has been actively working on it, it's seemingly far more likely to be on WP7 phones