While I feel quite confident with HTML and CSS, it seems to take a bit of
pain to use Dreamweaver for wireframing, perhaps because it tends to force
you into detail too early, when you are still on the "vision" stage of the
process, and feel like a WYSIWYG tool would be more appropriate.
On the other hand, wireframing in the WYSIWYG way entirely without HTML also
feels wrong, because first, the target medium is Web so it's closer to the
reality to think in HTML, and second, HTML is a powerful and expressive
language, and quite a mature one.