Windows 8 upgrade issue

Here's the case, I have a confession to make: I'm running a pirated version of Windows 7 Ultimate. I feel kinda bad for this since I am a huge Microsoft fan. So I've decided to legally purchase a copy of Windows 8 when it's released. Here's the problem, though: I can't upgrade for 40$ since my Windows 7 copy isn't legit. Will there be a way to buy a standalone copy? I really want Windows 8 and I don't want to turn to piracy!