But, no, I really don't see a "win" in replacing <b> with the equally-verbose [b] especially since [b] already means something at PerlMonks.

on a us-english layout, you don't need the shift key =)

a big win I see is: much less badly formatted posts. many users don't seem to recognize that they have to add html-paragraph tags instead of just adding a blank line.

I'm not saying perlmonks should use bbcode; I see the conflicts with current markup, I'm only saying there are advantages over pseudo-html.