It's no secret that new users have trouble formatting their code as code, i.e. indenting it with four spaces. I think the terse help text off to the right could be improved a bit, but even if that were to happen, most people probably won't read it anyway.
Recently I have come to notice that even active users don't know about the "101010 button" in the toolbar though. Most recent example: zerkms, a near-10k'er.
"oh, I never "seen" that 101010 button and always formatted all sources manually here or in my notepad :-S"
"It was a lot of pain to format sql in pony-style with millions presses of space button. Btw, I've seen it is a button but haven't idea what is it for and did not want to discover it. Meanwhile I've used link, quote, and picture buttons a lot of times. :-)"
I think the visibility/discoverability of the toolbar (buttons) may need to be enhanced, and/or a more visible introduction should be provided for newbies. Of course I realize this can only go so far, and especially on a site for programmers, users are expected to bring a bit curiosity and sense for discovery with them...
Just my 1.68 ¥.