Will there be more seasons of sekirei if so when...? (Exactly)?

There's no exact date yet. The second season is called "Sekirei -Pure Engagement-"

EDIT:

According to Wikipedia, the second season would be released in winter 2009.

Pure Engagement will be releasing in Japan in 2010.

Unfortunately I think Sekirei was a victim of being canceled. Quite a few anime have been cut short either because of funding issues or simply because they weren't popular enough. One of my favorites "Candidate for Goddess" was cut short at 13 episodes for some reason of another. Sorry, but you're going to have to find another anime.