In a perfect world, Toxaris, your expression would work fine. But oftentimes, spans are nested... which means it could easily replace the wrong closing tag. Consider:
Code:
<span style="font-style: italic;">These words are normal, where <span style="font-size: .75em;">THESE ONES</span> are simulated small-caps.</span>
Your regex wouldn't work correctly there. I believe Dreamweaver's search & replace tool is (at least partly) based on a parsing engine that
knows which closing tag goes with what opening tag... and would handle it correctly.
Matt's right. While
I probably wouldn't get a lot of use out of such a feature, I can see how many might find a feature like that quite handy. Meaning a feature that would allow you to modify/remove an element having a certain class--a feature based on an engine which was
aware of the paired-tag nature of (x)html and could always find the correct closing tag without fail.