Ravenclaw is the intellectual house, the house, the one that sits around tossing ideas out. It's the "clever" place to be. Naturally, one would assume that it would be an intellectual environment, very similar to... oh, let's just say the scientific community, because scientists are traditionally cast as the geeks.
I find it interesting that, from what we see of Ravenclaws (which admittedly isn't very much -- just Luna, really, and some of Cho, but not really very much of Cho; she's in an emotionally unstable place and can't be expected to be acting her normal self and therefore isn't a prime example of JK's Ravenclaw), we don't see a similar attitude as an intellectual (scientific) community. Luna, who is the main Ravenclaw, is full of crackpot theories and easily believes outrageous claims that have little backing. Now, we look at the scientific community. I do not assert that scientists don't believe some pretty stupid things: I'm sure that quite a few of them are d0rkuses like that. I do, however, look at scientific theory history and see that intellectual communities are slow in taking up new ideas.
As example, I would like to bring up Mr. Tesla, the AC motorman who was pretty much a joke in Europe for his claim that an AC motor could be created. The European intellectual community simply didn't believe in his ideas. When he came to the US, he got one of the big science men (I should know who but don't) to go with what he said, but the point still stands -- the intellectual community to which he belonged didn't take up his theory and dismissed him as a crackpot. It wasn't open to new ideas and change; it was stuck discussing old ideas and looking high and mighty about them.
Next, I'd like to bring up impact theory in relation to the extinction of the dinosaurs/creation of the moon. When the theory of a large impact which caused a chunk of the earth separating from the main body of the planet and creating the moon was introduced, it was not a popular theory. If I remember correctly, the popular theories of the time were independent creation and molten spin-off (but don't take my word on this; I haven't even thought about this in nearly a year, and what I do remember is from a series of lectures, not the book I was supposed to read or the notes I was supposed to take, because Lord knows I didn't do either). Until some serious evidence in support of impact theory was found (the evidence was mostly found in tektites, which are basically very smooth little beads of glasslike material which are created when high force impacts occur, and the composition of the moon), the general astronomical community rejected impact theory. They just didn't go for it without a lot of evidence (and even then, there were a lot of skeptics. Now, it's the commonly accepted theory).
Therefore, I find it interesting that the most prominent Ravenclaw, Luna Lovegood, takes so much on blind faith. There certainly wouldn't be very much evidence for most of what is printed within the Quibbler, yet, she pretty much agrees with all that it says. As Ely pointed out, there is also the geek stereotype of the sci-fi novel nerd, who gets engrossed in fiction and goes a bit wacky because of it. That wasn't ever how I personally saw Ravenclaw; I saw it as the sort of snooty house where everybody sits around and discusses Locke and Plato and politics.
Granted, Luna is really the only example given from her house. There could be lots of Ravenclaws who are exactly the Philosophy discussing type. I'm just saying what I saw and how it disagreed with what I perceived.
To sum up: I was surprised by Rowling's portrayal of Ravenclaws in OotP, though not necessarily upset by it.
That didn't come out quite right, but I think you guys get my point (there isn't quite one).