This is a great example of just how rage is going to work, and how the normalization of it will (likely) function across the entire system. If you have 10 rage, a heroic strike is going to cost you 33% of that, which means after the ability is fired you'll have 6 rage left. If you have 100 rage, a heroic strike is going to cost you 33% of that (up to a cap of 30), which means after the ability is fired you'll have 70 rage left.
This is the first real look at how abilities will change in Cataclysm, and is quite noteworthy for those wanting a glimpse at what's in store.
Edit: There's some confusion about Ghostcrawler's statement above and how it conflicts with Bornakk's original normalization post. We're not exactly sure which version of heroic strike is correct, however we're assuming Ghostcrawler's clarification is the "right" version. As with everything about the alpha/beta, you should remember that nothing is set in stone and it all can change.
Comments in this post have also been disabled since the negativity was getting out of hand.