Happily, I haven't posted anything recent enough to be affected by yesterday's Blogger meltdown, but I know that several of the blogs I keep track of lost their latest posts, possibly temporarily, possibly forever.
My first thought after reading about all of this was, "Huh, I guess I'd better be more diligent about backing up my blog." You can do that in Settings > Basic - there's a link near the top that lets you export your blog. This includes both posts and comments.
It occurred to me that I've never had an opportunity to try restoring a blog using a backup. That's where my test blog comes in handy. I have heaped all kinds of abuse on my test blog over the past few years, messing with its templates, fiddling with its code, adding widgets I'd heard about on other people's blogs. Anything I have wanted to do to this blog that in any way made me nervous was first tried out on my test blog - a good thing, too, since I sometimes messed up my test blog in spectacular ways.
So, I tried importing backups of this blog into my test blog. First, I imported a somewhat older backup. The import took a few minutes, possibly because I've got hundreds of posts. I did not have the "Automatically publish all imported posts" box checked, because I figure that, unless my blog is completely destroyed, I'd probably only want to publish a few posts. There is no option to just import a few posts, by the way - you can only import the entire backup.
All of my imported posts, plus their comments, ended up in the "Imported" area of Posting > Edit posts. At that point, I could choose which particular posts I wanted to publish, and then I could use the Select All feature to delete the rest a bit more quickly.
I was curious, though, about whether Blogger would be able to detect duplicate posts and prevent duplicates from being imported. That would really be helpful if you only had a few posts you needed to restore and wanted to use the "Automatically publish all imported posts" option. With that in mind, my next step was to try importing a slightly newer backup. The disappointing news is that it doesn't look like Blogger has any kind of duplicate detection - every single one of the posts imported, even when they were exact duplicates of older posts. I tried publishing a few duplicates, and they published just fine.
From the look of things, if you remember to back up your blog often enough, restoring it is pretty easy. I would advise not checking the "Automatically publish all imported posts" box, unless you were completely restoring your blog or adding you posts to another preexisting blog (importing your backup does not delete posts that have already been published - I had some test posts in my test blog that survived the import process just fine).
That said, even though I've tried to remember to back up my blog, I haven't made a practice of backing it up every time I post something - I could have been caught in the meltdown just as easily as anyone else. I guess I'll need to remember to export my blog more often. My last backup was from almost a month ago.
Anybody have anything else to add about backing up and restoring Blogger blogs? Since it backs up the posts and comments, I'm assuming it also backs up the pages - can anyone who uses Pages confirm or deny this?