Well, as said on IRC, I find it makes the code a lot harder to follow for languages with explicit type specification, where the type is an important thing and it introduce a keyword.  When you have to lookup the type of a variable and the only clue you have is that it's on the 50 lines above the current one doesn't help much.

Though, it's probably not a show stopper now we supposedly have switched to C99 or something -- but here it'd even be better to follow Exuberant-CTag's rules if this parser could get integrated back to them one day (though given their responsiveness it's quite unlikely actually).