Don't you think the explosion of the number of communities is fragmenting the space uselessly? Lately you don't even know if you need to send your question to Super User, Server Fault, or Unix & Linux.
Note: I agree with this: Too many Linux sites
Notably this fragmentation results in the creation of a lot of accounts, which thank god, is just one click away. But you end up with 101 reputation points everywhere. Also I'm not aware if search boxes do cross-community queries(?).
Another thing is the more questions that can belong to multiple communities, the more you lose the network effect.
I am not alone with this concern, and Robert Cartaino gives good hints about why fragmentation looks bad at first, but may have reasons to be accepted, in the article Unix and Ubuntu: Why Both? .