It's both actually, in a very weird way. Alpha 2 will run from datacenters but on small droplet-nodes. They could use some very big servers but that doesn't test for vaults from home again. So I guess several hundred small nodes. And what David is referring to is probably the Disjoint Group/sections part. So 8 nodes to start the network, then another 10 join and the network will split itself in 2 groups. Another 10 extra nodes and another split occurs. The nodes decide this for themselves, no action from any human/server needed. And the great thing is: they will keep all the data secured. Each chunk of data is stored by 8 nodes. If 1 of them crashes the other 7 will find a new node to get back to 8 again. This is decentralized as well.

https://github.com/maidsafe/rfcs/blob/master/text/0037-disjoint-groups/0037-disjoint-groups.md

Next to that we finally have Mutable Data in Alpha 2. Some community members already building a "Youtube":

https://safenetforum.org/t/safe-tube-release/15690

And this is what sets SAFE apart from all other P2P and crypto. It really allows for decentralized stuff. Metamask for Ethereum is cool, but it still depends on servers somewhere and now has 100k users:

https://twitter.com/metamask_io/status/897988358911266816

So the Ethereum idea was to decentralize stuff, but now 100K are moving to servers again as they don't run full nodes with a bloated blockchain. This is something SAFE fixes. Although it takes some time