I'll tell you exactly who is behind this.
Overstock.com is up here in Vancouver handing out baseball caps with the letter "O" on them. No literature, no message, no nothing else - just baseball caps with an O on the front and overstock.com on the back.
So, for fun, myself and a few other people have been telling people that Oprah is coming to the ICANN conference, and the guy from Overstock has to keep explaining, "No, it's not Oprah".
We also told him that he can't just get o.com, but he'll also have to get all of the typographic variants.
"What do you mean?"
"You know, like, what will happen if you have O.com and some other guy gets 0.com (the numeral zero)? Or suppose they start releasing international character sets and someone else gets O with an Umlaut or an accent? You're not going to let yourself get screwed by just getting that one letter are you?"
The guy seemed genuinely concerned. What a hoot.
But, yes, I agree with the comments above. Instead of releasing just a few single-letter domain names, ICANN should release millions of them so that everyone can have one.