I installed and ran Minecraft on a fresh install of MacOS 10.9, created a new profile that allows development versions, and clicked Play.

I noticed the download was taking a long time so I flipped to the logging tab in the launcher (see attached file). It seems the launcher tried downloading files too quickly and the server temp-banned my IP address.

When trying to download one of the files in the log:

https://s3.amazonaws.com/Minecraft.Resources/sound/random/bowhit2.ogg

I get:

<Error><Code>SlowDown</Code><Message>Please reduce your request rate.</Message><RequestId>767C530ABF5E64E8</RequestId><HostId>6IP69BNprQvK8SKmtJ7jxRqxO4ouAF2aCmF8vHSPkGa+pdX/AxLPbSjDpOTwH1kr</HostId></Error>

I just tried again at 4:38PM Eastern time on November 16, 2013 and got the same error message. This issue initially happened around 20 minutes ago and I'm still unable to download files.