In fact, Ajax really is DHTML with the xmlhttprequest object thrown in. It is amazing to think how one object can change the whole playing field.
As things currently stand in the ajax field, we almost have two extremes going on. At one end of the continuum we have developers building all sorts of complicated JavaScript tags that in most instances are unnecessary and are overkill. At the other end of the scale we have these little examples floating around the Web that demonstrate how to load xml into a document or do some ajax centered form processing.
While both ends of the spectrum have a part to play in the progression of the Web, I am not convinced that the principles of ajax and how they can best be leveraged by a developer have been conveyed as well as they may have.