Awesome!
Will you add this to the to do list?

Yeah its fairly easy to implement. its a good idea.

Blogger has this for text boxes when you make a blog post, and it works fine for Mac under Safari and Firefox.

story of my life!

Wordpress does this too.
What I think happens, is that it works in PC but not Macs. But I could be wrong.

I can't say for sure, but I think the JS overrides browser shortcuts.

Oh, I didn't know JS could capture keyboard. Won't this interfere with browser shortcuts though?

There is a simple javascript app that can do this. Plus, as I stated, there's another forum which has this feature.
The actual input text box doesn't need to be java for this to work.

I've used this myself once, and it worked great!

Not possible, I think. Keyboard commands are going to your browser, and it will do whatever it thinks it's right they do. There's however the option of graphical buttons on the edit window that will do the same thing.

Edit: Might be possible if the editor was an application (Flash/Java) I guess

Would it be possible to implement keyboard shortcuts to BBcode tags?
I know another forum which has this and it's really convenient.
Example; Ctrl + i produces opening and closing italics tags and places the cursor in between. The same keyboard combo with text selected tags the selected text as italic.
Sounds cool?