I have a task in front of me to migrate a blog site from Drupal to Blogger, and fortunately I just found that someone had written a script to do exactly this. The task is a subset of the larger "Migrate From Drupal" task in that it is a conversion from a Drupal blog to specifically a Blogger blog. That's a little different from the model I've envisioned so far, which is an export of content from a Drupal site into a neutral format that could conceivably be imported into any other website platform. The latter, exporting into a generic website content format, would be preferable but in the meantime I do need to convert this specific Drupal site into a Blogger site.
Blog post: http://christophe.vandeplas.com/2011/05/migration-from-drupal-to-blogger.html
The interesting thing about this script is that it doesn't even attempt to work with the Drupal API. It just goes into the database and pulls out data. So obviously it's going to miss any CCK fields you've defined. On the other hand the script is simple enough for someone to add to the queries to pull in data from CCK fields. (note: the script is Drupal 6, so CCK is the correct term)
Another guy took the above and created a Drupal 7 version
Another blog post gives detailed instructions on its use: http://www.elaboratelymundane.com/2012/12/drupal-to-blogger-migrate.html
Another fellow concocted a Rube Goldberg style method where you would move the Drupal content to a Wordpress site using the RSS feed importer in Wordpress, then use a Wordpress to Blogger service to import that to Blogger.
The wordpress2blogger converter is here: http://wordpress2blogger.appspot.com/
Source code: http://code.google.com/p/google-blog-converters-appengine/
It's actually a generic blog converter doohickey and the matrix of conversions are here: http://code.google.com/p/google-blog-converters-appengine/wiki/ProductConversionsMatrix