We've made a slight change to the way our blog compose tool works... for the better.
This change aims to clarify the two editor modes -- normal (where you simply type your post, using the blog editor toolbar for formatting changes) and HTML (accessible by selecting the "Edit HTML" checkbox you'll find in the editor).
Note: If you don't already write HTML for your blog entries by hand, there's no need to start now! You can still use our blog toolbar for simple point-and-click formatting -- this is just a notice for those who like to get a little more in-depth.
As the editor previously worked, one could manually enter HTML tags into either mode and, upon saving their changes, have them applied to their text. The downside to this was that it was difficult to enter HTML code for display (such as when writing a post explaining to others how to format text in HTML). And now it's easy.

So if I wanted to show people how to point others to a different site, I would simply enter the following with the checkbox
unchecked:
<a href="http://www.petitiononline.com/ecch2004/petition.html">Help bring Chocodiles to the east!</a>

And if I wanted to make it appear as a link within the entry (such as when copying and pasting the HTML from the previous example), I'd enter the same text with the box
checked, which would result in a link like this:
Help bring Chocodiles to the east!
Yes, it's that simple -- if the box isn't checked while HTML tags are entered, the markup won't be interpreted.
Source:
http://multiply.multiply.com/journal/item/160/New_improved_HTML_editing