Yeah. Imagine upgrading your client and it erasing your wallet? That doesn't happen, but kinda scary thought.

Get your encrypted wallet data file in the cloud, (I love how that's so mainstream now. To the cloud!) Or at least OFF your computer in some form or fashion. 

Also, have TWO "wallets," one for every day use, and one for savings. I do it. And I use boot-from-usb key to do it. And also saved encrypted wallet off the usb key. I put a copy on my web server, on my 8MB SanDisk SD card, lol, and I printed it out in hex. (geek)