First week of the month, so must be Viz! Well, mostly.
Certainly the title that caught my eye the most is the manga biography of Che Guevara, which Penguin Books is putting out. Unlike most faux-manga bios, this seems to have actual Japanese artists. If you like Che Guevara, check this out! (How often do I get to type that?)
Bandai has another 4-koma volume of Lucky Star coming out. And DMP has Bloody Kiss tonight, which seems to feature yaoi vampires, making it the most licenseable title in the history of the world.
And Viz. New Gintama is always welcome, this one wrapping up the long arc with the cursed otaku sword. New Bakuman will likely give me mixed feelings, but I'll read it anyway. Special A and Crown of Love put out their final volumes, though I think everybody but me dropped SA a while back. There's also new Otomen, hopefully with more Ryo after that last cliffhanger, and new Kimi ni Todoke, which continues the arc focused on Chizuru.
As for debuts, I'm very interested in Genkaku Picasso, a title from the author of Short Cuts, which sounds vaguely disturbing. Though possibly not as disturbing as the cover to Kurozakuro, a new Shonen Sunday title which will not eat you if you buy it, despite those teeth. And a new shoujo series, The Story of Saiunkoku, comes from Kadokawa's Asuka magazine, and no doubt has an anime tie-in or two already.
What's interesting you?