I don't mean to sound rude, and it could be that others disagree, but IMHO, editing access should only be granted to people with a basic understanding of the english language, and people who have demonstrated either knowing how to spell, or utilizing spell check.
From my understanding, the point of the wiki is to have somewhere that all information is summed up in a clear, concise, and easy to read fashion, and I don't believe spelling and punctuation errors fit that bill.
It really doesn't take too much effort, and all it takes is a little less laziness to check the spelling and grammar.