<2 cents>
The amazing thing for this extension is they have Wordpress behind them.
The pricing shows the quandry for all gTLD solutions. They are all trying to figure it out. Do they go high, or flood the market? If they go high, they lose the mass market appeal and benefit of lots of sites been built. That turns into a vicious de-compounding cycle.
If they go low, they miss some revenue, and they might not get so much building as they thought. But, WP must have a great chance of trumping that.
What I can't figure out with this .blog - is why i don't like the sound of it (the dot and the blog together). It's just not working for me. Blog is one of the most amazing new words we have. It's one of my favorite words.
If I was setting up a blog and I run an infrequent one, I would definitely still want a .com.
</2 cents>