Sorry for resurrecting an old thread, but I found this when trying a quick search on how to export my desktop Firefox bookmarks to my Xoom.
This may have been answered before, but since there's no bookmark foldering in the Android browser (CORRECTION: see EDIT below), I thought to try exporting my Firefox bookmarks to HTML (which keeps the bookmarks organized by folder in an indented list), copying the file to my Xoom, then accessing it using a file:// URL (for example, file:///sdcard/bookmarks.html ) in the browser. It worked, and I bookmarked *that* page for easy access.
Just tested on my OG Droid, and it worked nicely there, too.
Unfortunately, this solution doesn't allow easy add/delete to those bookmarks, but refreshing them is a simple copy-and-replace over the bookmarks.html on the device with a new export from Firefox on the desktop.
EDIT: there *is* bookmark foldering in the Honeycomb browser, but it's difficult to discover. Edit a bookmark and under "Add to", tap "Bookmarks". Tap "Other folder..." to create new folders and subfolders.