The ESRB website appears to be somewhat of a thorn in Atlus's side lately, leaking information about upcoming games before Atlus seems to be ready to release it. The newest leaks are from ratings for Steal Princess and The Dark Spire, both revealed to be possibly coming to North America from Atlus sometime in the future.
While Steal Princess (the spiritual sucessor to Land Stalker) for the Nintendo DS is known to be developed by Climax Entertainment, The Dark Spire's true identity is still as secret as the Batman's. There is some speculation on Siliconera that The Dark Spire is a localized version of Genmu no Tou to Tsurugi no Okite for the Nintendo DS. Steal Princess is an isometric action-RPG which was released in Japan on July 24, 2008.
Both games are rated E10+, though RPGamer does wish to point out that The Dark Spire contains an "erotic panda" of some kind. Official press releases for both or either game could be coming soon.