I see what you mean about the indentation guides. It works (and shows up) especially well when you have multiple levels of indentation.
One thing I've noticed about the regions is that autocomplete is still showing up. I suppose some people might want it to work for preprocessor evaluations, so that their macros will show up, but could you look into disabling it if the first three letters of the line are "#re"?
Also, I'm not sure how easy it might be to modify the Scintilla control's folding further, but I really hate the way that it collapses things. If it's too much work then just ignore me, but the way Visual Studio does it is very nice. Basically it would look more like:
[-] void OhMyGod()
| {
| // fancier folding
[-] while (true)
| {
| // Indentation guides
|- }
|- }
...and when collapsed...
[+] void OhMyGod() [ { ... } ]
So instead of collapsing from the opening brace, it would collapse from the corresponding function name or if or while statement, and instead of that hideous line underneath showing that there is hidden code, it would show a greyed out bit of text. Again, if that's not really feasible then just feel free to ignore this bit.
Oh, and more graphics filters! Invent new ones, I don't care, just give me moreeeee!

Oh, oh, and...Dual will love you for making it so he can click on the line numbers to select the text again. He hated the tedious act of having to click on the line, press End, hold Shift, and press Home. I mean, what is this, the Stone Age?
