Something like this is highly low priority. In some senses, it would actually break some really minor things, like if you're trying to emphasize something that has an asterisk before (Though in forums we mainly use parentheses, such techniques would be used for advertisements). This would mean using the asterisk system would break simple (highly used maybe?) asterisks (e.g. *
Here I am...ROCK YOU LIKE A HURRICANE). But this is indeed trivial, since the whole idea is just silly.
What's the deal with [nobbc]...? Come on...It's a rare hidden feature, and unless you have a slower WPM, it's really nothing. Programmers get it tougher...
I guess you can see my position. I'm indifferent on it really...I'll just use [nobbc] anyway unless I find that * is more convenient (Which it isn't, since I usually don't touch the Shift and Number Keys).