Also, while I'm not commenting on Linode's response to the incident, ultimately the security of your information is up to you. The owner of the stolen Bitcoins has publicly stated that he learned a lesson: encrypt your data.
Your server, your data, your information is only as safe as you make it. Even if everything is fully encrypted and all a hacker could do to mess with you is delete your instance, you should have offsite backups of your important stuff. Always assume you're going to lose everything. Whether it's hardware failure, hacking, or a simple mistake, treat a gun like it's loaded.
Encrypt your important data. Use two-factor authentication on privileged accounts. If you want Bitcoins to be a currency, then read up on Payment Card Industry regulations and really understand how to keep a currency secure.Hire an auditor if need be. Everyone is going to be hacked, everyone is going to be embarrassed, and your data is never secure unless you make it secure.