Kodansha Comics effectively replaced Del Rey Manga in late 2010. Their release plans then were a mix of new-to-US titles and reissues, some in omnibus form. Some series picked up where Del Rey left off, particularly if they were popular titles.
However, the Kodansha Comics Twitter account has some bad news for fans hoping to see other series return:
@starlightk7 Sorry, barring some special circumstance we’re not rescuing any more Del Rey Manga titles.
— Kodansha Comics (@KodanshaUSA) January 16, 2013
Sorry, fans, it’s been cherry-picked, and they’re moving forward. However, as is pointed out in response, some of the series previously published by Del Rey Manga are now appearing on JManga.com, including School Rumble, if you don’t mind reading digitally.