It does now support Hulu Plus / Hulu+.
Note that I'm looking for a Hulu+ account myself to test some other features. (I'm outside the US. Someone gave me access to develop, but then withdrew it again.) If you (or anyone) could share access that would be appreciated. Just sharing the "auth" file that get_flash_videos writes to .get_flash_videos/hulu is enough. (It doesn't contain your password, just a token that's valid for a month or so usually.)
If you can help please mail
zakflashvideo@gmail.com