V2 Themes FAQs (new theme system introduced in 2011.3):
My site was just updated to 2011.3. Where is the new style designer? Once your site is updated your existing themes will use the old theme system. When you navigate to Themes > Add New Themes here is where you'll see the difference.
Can I convert my existing themes over to the new theme system? No. The new theme system is fundamentally different and is why there is no option to convert existing themes.
Can I export and import themes? Yes. Newly created themes can be exported and imported.
Can I manage my theme using Dreamweaver, Expression, etc? Yes. So far we have a video 'Connecting Dreamweaver to your themes' on the new theme start page section for 'Learn How to Create and Design Themes'. Using editors outside of the AmeriCommerce theme system is for advanced users only and use of a 3rd party system or end user input could break the layout or cause undesired and difficult to repair results. Support to correct such issues is billable and we cannot assume responsibility for such action. There is a powerful code editor built into the system so you may find it unnecessary to use another editor but we give you that choice.
In depth KB articles that relate to the new theme system (greyed out are Coming Soon)