So far here are my thoughts on it as a a hosted blogging tool.
1. It's hosted, so like type-pad no worries trying to install into your own web space if you want to avoid technical stuff.
2. It's free, this alone is tempting.
3. It's fast, very fast, and makes type-pad seem slow in comparison. Maybe as service get added it will slow down, but for now, it's a delight to use.
4. It's simple, really really simple, and intuitive.
5. The output from the limited templates looks gorgeous.
So get over to wordpress.com to register your interest for an invite.