The premise of agile teams is persistence: work like you train, and train and work together. These practices are the backbone of good benchmarks -- like velocity -- which is the heart of agile planning.
Then, of course, there is the counter argument: such familiarity drains the innovative spirit; there's not enough exposure to new stuff that comes with socialization -- it takes a village, etc.
And, then there's the counter-counter argument: with the right space planning, even persistent teams will wash up against many socialization opportunites from the lunch room to the rest room to the coffee bar (I don't think water coolers are much in evidence anymore, replaced by the K-cup machine)
So, is there a right answer: does persistence choke off innovation, or does the persistent team provide the vehicle to act on an innovative idea and get it into production more likely/more better?
I actually line up with the latter: persistence for quality benchmarking and effective work practices, but open plan work for the "osmosis of communication" as Alistair Cockburn would say.
And, of course, there's the Allen Curve that gives guidance on how "open" such open plan workspace should be. Innovation falls off dramatically (exponentially) with lack of socialization.