Hi,
I've had a very quick play with the Blend theme and thought I'd post my initial thoughts:
Lovely theme with excellent customisation options. I've not delved into the code yet to see how it's all put together, but I'm sure that will be lovely too.
Some observations:
The sidebar off for posts and pages setting doesn't work - it never seems to save the option on my install.
A colour scheme preview would be nice - you currently have to change the setting, save it, and preview the blog. It'd be nice to use WordPress 2.6's built in theme preview functionality, or maybe just display an example gif to indicate the general colour scheme.
Footer widgets disabled - this option is greyed out and there's no immediately obvious way to enable it.
That's all for now. Like I say, just quick observations from five minutes playing earlier on. I'll have a proper look at both of the available themes on Monday probably - got to head to Wales tomorrow for a wedding.
Hope that's useful.
Dan.