Two questions: Looking for good GPL Themes and why should I go GPL?

I’m looking for some good themes to use for some non-commercial blogs. Ideally, I would like to support the GPL part of this community and was looking for some professional GPL based themes of high quality. I have some experience with Carrington, but is also looking for other good themes and wish to ask if anyone could give me some pointers?

That was the first part of the question, the second is a bit more about GPL ideology. I’m a bit new to the WordPress community so please be(a|e)r with me 🙂

I see that WordPress.com now has added support for the Titan theme, but the author also sell a Titan Pro version of the theme. I have also heard that Automatic are planning sanctions towards commercial authors (from webmaster radio) and that they don’t want to endorse non GPL authors. So why does Automatic endorse a commercial theme author and why should I want to go with the GPL community when Automatic seem to endorse commercial theme authors themselves? Is there something I’m missing?