I disagree strongly that "culture" (a word that's constantly misconstrued by executive trying to justify a horrible workplace) has any bearing on whether an open plan is successful. It much more strongly depends on the type of work being done.
A police bullpen or typing pool may be fine in a big open area. The same goes for sales and marketing types. However, if you're talking about any work which requires stretches of concentrated effort then it's just a Bad Idea. Engineers? No. Programmers? No. Accountants? No. Any kind of researcher? No.
the lower real estate costs
This is the only real reason they're pushing this model. It's a clear terminus of the erosion that's led us from offices, to cubicles, to the little half walls, to just acres of desks. Well, that, and wanting to look hip by copying other companies who are doing it.