I upgraded to 3.0 on my main blog then consolidated my standalone WP installs into the 1 3.0 multisite install, with domain mapping, (using the instructions in the codex).
I just noticed that images are not appearing in the old posts that have been imported. The image URLs still point to wp-content/uploads/{date}/{filename}, however, this doesn't seem to map to anything in 3.0. I had hoped that those WP URLs would be updated in the import process, but apparently this hasn't happened.
What's the best solution here - should I be adding a rule to my .htaccess that maps /wp-content/uploads to the wp-includes/ms-files.php, or is there another, less hack-ish, way to get my images to display.