Earlier ANN reported on the first Blade of the Immortal novel turning up on Amazon.ca. I did a little digging annnnd.. voila, it's listed on the US Amazon as well. Here's the summary/solicitation text courtesy of the ANN article.
Blade of the Immortal: Legend Of The Sword Demon (novel)
Hiroaki Samura (artist), Junichi Ohsako (author)
Dark Horse Comics
November 15, 2009
Publisher's description: "The first novel based on the worldwide sensation! Rendered immortal by an infusion of mystical worms that can repair any wound, the masterless samurai Manji wanders the hillsides of feudal Japan, his quest to slay one hundred evil people to atone for his past sins. By his side is the young woman Rin, an orphan who seeks vengeance for the murders of her parents. Driven in a quest for absolution, the two have faced many deadly challenges, both natural and supernatural. But can they survive their greatest battle against the all-powerful Inugami?"
The US Amazon listing has it priced at $11.