Was just thinking, and I believe Blizzard should and WILL put the new characters in the cash shop. It's a win-win situation for everyone, the players and Blizzard for a few reasons. The amount of money this would bring in would be RIDICULOUS. This isn't some dumb pet or sparkly horse, this is something that's been hyped up for years that pretty much every player would want. The people who won't like the new models and want to keep the old ones don't have to buy them so there's no issue with those players.
If they sold the stupid helms for $15 and people bought them, think about how many people would pay $10 to unlock a character model for a race, and then maybe a package deal that would unlock all races for $75. You can bet every kid would be stealing there parents credit card to buy them on day 1. I personally would buy 2-3, human, orc, and maybe gnome.
From a business standpoint, it would be absolutely retarded for Blizz NOT to sell new models and to just give them away for free. You KNOW people would bitch about it but end up throwing gobs of cash at it. We saw it with the mounts, and then with pets. The bitching only lasts like 2 weeks and then everyone forgets and doesn't care anymore. History will repeat itself, and Blizz knows this. If they can pull of selling helms for $15 that people used for like five days, then this would most definitely fly.
I wouldn't be surprised if the amount of money generated from character model sales the first week would rival the amount brought in from first week sales of a whole new Xpac or even Heartstone.