Many times, but that's not necessarily clear or simple. The generic delta-generation tools we've tried in the past just choke on our files; note that the full-history dump of English Wikipedia -- the one we're most concerned about having archival copies of available -- is over 350 gigabytes uncompressed.
Actually, I just downloaded enwiki-20060518-pages-meta-history.xml.7z and when I did a "7za l enwiki-20060518-pages-meta-history.xml.7z" it said that the archive would be 692686106434 bytes (645 GB) uncompressed. Is that inaccurate?
~MDD4696