That's what the announcement said. "A poster Kubo-sensei drew with all his might." Here it is--it's too big to get an HQ of, but thanks to Mel and Neko of BA we have these scans. And guess what? The way Kubo drew Dark Rukia, she isn't wearing any underwear!
Look! No undies!
This poster was included with this week's Shounen Jump, which was a double issue, which means we won't have any new Bleach chapters until the New Year. But we all got cliffhangers and Kabooms (Naruto, haha) and presents to hold us until the next issue.
ETA: HQ Wallpaper thanks to Turlte is here