convert 1.6 themes to 1.8

[Eric]

Unfortunately you'll have to manually move them over. New templates were added, templates were changed, selectors were updated, etc.

That said if you kept most of your changes in CSS (For example I believe Justin's Apart themes only modified 6 templates or so), then most of the site will retain it's design by adding in the CSS. After that it's as simple as updated a few templates with big changes in 1.8 (Header/Footer/etc.).

It's certainly easier than say, porting a design to another software. I do wish there was a list of changed/added templates though.