I don't think that's such a big deal, at least if you use my suggestion. If you're writing a simple post, you probably aren't going to update too much anyway (it's usually only the complex ones, with code, etc. you really need to update.
But even if you do, it won't be too complicated to realise there have been some tags added - it's mainly the typing of the tags (when you don't need any other HTML) that's annoying, rather than having to know HTML, or whatever.
To enhance this posting 'mode' even more, maybe PerlMonks tags could be left active, or have a separate check box to turn these off. A lot of my posts only use PM tags and new lines. I don't need HTML
