500 Internal Server Error

When trying to install any of the purchases from the App Store, I receive the following error:

The server gave an error during download: 500 Internal Server Error.

I have just purchased OSX Lion and this is getting kinda frustrating. Is this a regular occurance with Apple or just an overload of Lion downloads? If it is on account of Lion, they should have been prepared for that considering it's only available as a download through the App Store...

Are there any known solutions for this problem or is it only on Apple's end and you simply have to wait it out?