Fear not! It is still possible through use of lowly TextEdit.
Fire up TextEdit and format your text however you would like. It supports bulleted lists, numbered lists, colors, etc. Once you have the text the way you like it, highlight it, and copy. Switch back to Mail and paste the text into your mail message. Mail should preserve all of the formatting that you made in TextEdit. And you can keep on merrily editing. If you want even more than TextEdit can provide, you can do the same in other HTML editors (like DreamWeaver).
One thing to be wary of -- Mail will attempt to create a plain text version of your email as a secondary attachment for people who are using an email client that understands text only. This plan text attachment may look rather strange, depending on how fancy you get.

