The template in a Layouts blog is written in XML. You can't use HTML in a Layouts template.
For those of us who are used to HTML, that's a major problem. But it shouldn't be.
Whatever you could do under Old Blogger, you can do in Layouts Blogger, but you don't edit the template. An very few examples:
- Hidden linklists.
- Linklists with pictures.
- Multi-Style Topics.
- Videos from Google Video, or YouTube.
- Visitor meters.
And since you don't edit the template, if you want to change to another template, just select Pick New Template. All page elements that you setup in this template will work equally as well in the next.