Finally, at this June 2010 Blogger Template Designer has officially launched for everyone. Open your dashboard and you can find Design menu.
What we can do with this new blogger template designer?
- Beautiful new templates. Blogger have designed 19 brand-new templates, with more on the way. You can quickly give your blog a great new style by selecting one of the new templates.
- Separating design from layout. Designs are completely defined in CSS (Cascading Style Sheets), meaning that any design can be applied to any blog layout, making templates more flexible and unique.
- Hundreds of free, professional background images. We've paired up with iStockphoto to offer you hundreds of gorgeous background images at no cost.
- A single control to change all your design's colors. With other platforms, users have to define every color in their blog separately, making changing the color theme of your blog a tedious task. The Blogger Template Designer lets you change all the colors in your blog at once, by changing the Main color theme.
- Pixel-perfect layout manipulation via smooth resizing. You can define your layout down to the pixel via sliders that update the blog's preview in real time.
- A real-time preview sits below the design control panel. Watch your blog update as you create your template design.
- Keeping it simple. Throughout the Template Designer we use hierarchy to hide complexity from you.
- Complete control. Under the advanced tab, you can override a design's CSS and enter your own CSS in the editor and see your blog's preview updated in real time.
- Cross-browser support. Blogger handles cross browser support for you, so you don’t have to. Want a design with rounded corners? We give it to you in Firefox, Internet Explorer, and Chrome.
Source : Blogger Buzz
 Note: Selecting a new template will erase all of your customizations on the existing template, so if you have customized your template be sure to first save the current template at Design > Edit HTML click on Download Full template