Backup your blog guys. Under Settings> Other> Export blog.
Yesterday I started poking around the settings again and I noticed the option, which in turn caused me to realize I haven't made any sort of copy of the stuff I've written up to this point.
Just in case some thing happens.
I haven't been running this blog for even a year yet, but I know I would be pained if I lost all the material I've written so far.
It only took 15 seconds to download the XML file. Why not back up your blog?
Oh oh, don't forget the template, too. Unless you just use the default settings. I had to do a bit of tweaking with mine before the margins and sidebar widths ended up just right so I backed that up, too.