So the lead dev has a private key which lets him control all the MasterNodes? Why does he need to control all MasterNodes? In the future, will he be in control or is this just temporary and if so how long will this continue?
No, he does not. There is a private key for engaging the spork but that's it. This allows us to prevent forks for the time being while bugs are getting troubleshooted on mainnet when new features get rolled out.
LOL, so now the spork trigger is being fudded as a key to control masternodes?
1. The code for the spork trigger, which is used to keep the network from fragmenting while DRK/DASH is under heavy construction, is all in the open code, and you can see there that it does nothing but enable/disable enforcement of minimum wallet version, at least that's how I understand it, correct me if I'm wrong.-- and the previous wallet will have min. wallet enforcement from before so that a network manipulator will still be limited to how old a wallet he can use. The rest of the network will still reject bad actors.
2. This does NOT give anyone any control over any masternode, except it's owner.
3. It might continue to stay in place for some time because we're still improving the technology and it makes hard forks less risky, and the risk to the network is virtually nothing other than possibly causing masternodes to miss out on payments. This is a risk we understand, but it can not be avoided when introducing new or upgraded technology. And this very new technology is what gives DASH it's value.