A couple of episodes released so far:

Episode 1 - Ryoumi Subs
Episode 2 - Ryoumi Subs
Episode 1 - Imouto
Episode 1 - GNU Fansubs

"Based on a manga by Go Zappa & Sakura Takeuchi, serialised in Young Animal.

Haruma Kawagoe is an only child. A long time ago, at Christmastime, his mother miscarried the child that was to have been his baby sister. That night, young Haruma knelt down and offered up an earnest prayer: "Please make my mother well again, and please give me a little sister." Years have passed, and Haruma has nearly forgotten his prayer. But Santa hasn`t.... one Christmas, when Haruma is least expecting it, he gets an unusual present - his sister." -AniDB

Genres: Comedy, Drama, Slice of Life

Some links:
Official: http://www.chocosis.com/
AniDB: http://anidb.info/perl-bin/animedb.p...anime&aid=4350
Animenfo: http://www.animenfo.com/animetitle,3...to_sister.html
ANN: http://www.animenewsnetwork.com/ency...me.php?id=6674

I watched the first two eps from Ryo. The subbing was good in my opinion. The series itself was slightly funny and quite cute. And I have no idea what is the target audience. Well, maybe more episodes will make that clearer. Or perhaps I just can't distinguish (the probable reason)...

All in all, based on the first two episodes, this wasn't as close to Aishiteru ze Baby as I hoped (foolishly, I suppose, but that's why I picked this), but it was somewhat good by its own right, so I'll keep watching.