So the DAO was hacked due to a vulnerability in the way they wrote their smart contract https://blog.ethereum.org/2016/06/17/critical-update-re-dao-vulnerability/
The Ethereum plan is to fork the chain to specifically prevent the attacker from being able to withdraw from the DAO account.
So what is the DAO's connection with Ethereum, and what is its purpose? Why is the operation of the DAO so cruical to warrent a fork? I also see mentions of a company called Slock.it being involved somehow, what was their role in this ordeal?