As I am sure there are many others, like myself, whose very will to continue living hinges on getting into the Hearthstone Beta and finally playing it.
And the way I see Blizzard going about the Beta, aside from the Opt-Ins, will be a Supporter Beta Key. Aka, you purchase a pack of Micro-Transactions, and you get to play the Beta. As they stated, any points purchased and used during Beta to purchase packs will give you packs/etc on release as well as a special reward for helping test the Micro-Transactions. (And I'd really want that, maybe more so than the actual Beta... Nah, who am I kidding, BETA!)
So... What's the most everyone would be willing to "donate" to get into the Beta if they are doomed with such appalling a fate as not getting Opt-In?