Don't ask me to go any deeper.
Anyway, with New Blogger June/July 2008, comes a new setting, under Post Options.
Interpret typed HTML.
The phrasing there is confusing, to me anyway. What it means, in effect, is that typing "<" will display "<" and ">" will display ">", without any work from us, with "Interpret typed HTML" selected for that post. No more having to type "<" and ">".
In other words, in a single post, you'll be able to copy and paste raw HTML and have it display as raw HTML.
This feature may hasten the elimination of the toolbar in "Edit HTML", and make that mode still less usable for composing content. And this should make the New Blogger June/July 2008 Post Editor more attractive, at least slightly so.