Sorry for double-posting.
The theme song (opening?) for
Bakemonogatari will be done by
ryo of
supercell. (You know, the guy that
managed to sell 20,000 copies of his Hatsune Miku album on the first day. Link NSFW.) The title is
"Kimi no Shiranai Monogatari" (The Story You Don't Know). Vocal is Gazelle (of Melt 3m Mix).
More details in
the official single page. This will be his first "major" single release.