Time to test on Mavericks!
The "Start Install" button is not clickable.
For what it's worth, Hearthstone has never been installed on this particular computer.
On my secondary Mac, which had Hearthstone installed when I was previously running Mountain Lion, I am able to update and launch Hearthstone without any issues after updating to Mavericks. So it appears that the problem is isolated to the initial installation of the game after installing Mavericks.
If the dev team has any idea what sort of logs to gather, I'll gladly gather some to help look into this issue.
Console says this:
10/27/13 8:08:41.573 AM Hearthstone: 08:08:41.573 ERROR: [com.apple.audio.IOThread.client] AUHAL.cpp:2470: AUIOProc: AUHAL::AUIOProc: mono buffer too small (1024 > 512)
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