I've just started reading Tommi Brander's blog, Cogito, ergo ludo. So far I've found Tommi to be a consistently engaging writer and an imaginative roleplayer. His homebrewed persistent fantasy roleplaying system looks intriguing, but I think I'd need a pile of designer's commentary to successfully digest it. I do like the goals of the system and it does look like it fulfills those.
I was going to write about Tommi's division of play-preparation into sandbox, scripted, and volatile, but I need to think about it some more. I've always tended toward improvisation GMing and something non-obvious in there is speaking to me on that. I would just write a rambling post if I didn't ferret it out first.
In the meantime, go read some of Cogito, ergo ludo. Tommi's quality of writing and thinking on roleplaying is quickly becoming a personal benchmark for what I aspire to someday do.