Steve Bennett wrote:
"If we implement a parser that renders 99% of the current corpus of wikitext correctly, and we come up with a reasonable process for rolling it out without too much disruption, would you let us do it?"
I guess the answer would be yes. I'm not sure who all the angry comments in parser.php belong to, but they weren't kidding.
I think probably the new parser would also have to be faster than the old one.