I simplified the layout - a lot. I can't figure out how to incorporate my old logo, which is a disappointment. Maybe I'll try to whip up a new one. The nice thing about upgrading to the new blogger options is that certain things are incredibly easy to change without mucking about with html. But I couldn't figure out how to arrange pictures inside of the header or footer (which don't allow you the leeway of the other widgets).
I like being able to put links into dropdown boxes. My sidebar was getting way out of hand (a problem I've noticed on just about every single blog out there). I don't know why that's not a standard widget. Dropdown lists and attachable/detachable pop-up boxes would be useful.
I'm also disappointed that they haven't made an easy way to construct a more fixed layout (specifying the space between elements). I'm sure you can do it in the code but I haven't messed around with the widget code yet, which is like html but completely different.