I'm surprised that this doesn't have a thread yet, considering it's an ongoing series w/ 5 eps already.
First of all, it's by SHAFT.
If you didn't like their animation style in SZS or Hidamari, you won't like this either.
As for me, I'm ok with it, it truly shines at moments like the awesome OP.
[Spoiler=Short intro]Maria+Holic is about Miyamae Kanako, a new transferee to an all-girl's school called Ame no Kisaki.
She's a closet lesbian, and she's very bad with males- she breaks out in hives just by touching one of them.
The first person she meets however, is Shidou Mariya, the ex-chairman's granddaughter.
She's a school idol, and is a perfect in everything from intelligence to manners.
Kanako soon discovers however, that Mariya is actually a crossdressing boy.
Mariya's true personality is also revealed- a manipulative, sadistic person whose main goal seems to be popularity within the school.
Mariya threatens to expose Kanako's "preferences", and binds her to secrecy.
And thus begins their weird relationship together.[/Spoiler]
It parodies yuri anime like Marimite, has the random jokes of PPD, and has the self-despair moments of SZS.
Personally, I love the relationship between Mariya and her maid, Matsurika.
Matsurika is a bit of the silent type, but helps out her master in abusing Kanako.
Surprisingly, she also insults Mariya quite a lot, to which she replies something along the lines of "I'll pretend I didn't hear that, you shitty maid."
I like Mariya's voice when she's not acting like a girl, it fits her abusive nature quite well.

Aaaaaanyway, to those who still have spce in their viewing schedule, give it a try.
It's a SHAFT anime intended for comedy/yuri undertones, so don't go looking for a deep plot in this one.
You have been warned.