At the moment, Johnny is not ready for any websites to be hosted on it. When Johnny is setup, we will open signups to him which will balance Server Load, reducing the chance of 500 Internal Server Error.
At the moment, we have no intention of moving any current accounts to Johnny anyway. However, this intention may change in the future.
500 Internal Server Errors are usually caused by High Server Load. Please take a look at Stevie's Current Server Load in my signature.