Dr. Data (image from Ars)
We always say back up your iPad data. Do it often. It doesn't take very long. You just plug your iDevice into the computer and iTunes does the rest. If you still need some help, Apple has a very thorough explanation here, and it's worth reading if you're unsure of the backup process.
That said, sometimes people forget to backup. Trust us, that's never a good idea. You don't want to forget a backup. You know why? Because it's hard to recover your old data if something should happen and your iPad loses its information. That's where these folks come in.
DriveSavers is a company the specializes in recovering data from hard drives that have gone bad, and they have now added the iPad to their list of serviceable hardware, as seen at MacWorld. They say that their first customer was a CEO of a "large financial institution." CEOs can probably afford the $1,000 it costs to bring back your iPad's data, especially when said data is important information related to work. The rest of us may not want to spend all that money on recovering that stuff. See? We told you it's important to backup.