It *is* designated as a local cache, although you could distribute it via DSO - why you would do THAT is beyond me, honestly.
But using it as a local cache gives you the performance characteristics of a distributed cache with none of the benefits.
Let's assume you're using it as a local cache: every VM that you use it with, you get to allocate ginormous amounts of RAM to. Four VMs, 90G each (for example), and that's 360G of RAM you're using. And access to it is slow; the hot set for each VM will be fast (and likely duplicated), but any data not in the hot set is slow, almost as if were distributed in a worst-case scenario.
At that point, you're better off USING a distributed cache. But wait! With DSO you can distribute it, right? But then you're crushing speed *again*.
The fact that they got BigMemory out the door is cool. That said, the range of apps it's suitable for is very limited, and most would benefit far more from investing elsewhere, in my honest and humble opinion, based on running THEIR test and comparing numbers.