There was a lot of talk about Ethereum switching from PoW to PoS some time this year. Has the DAO and the Hard Fork delayed or otherwise affected when that might happen?
Purely from the perspective of the cold, hard code as it currently stands: no.
In the run-up to moving over to PoS, the difficulty of the mining on the network will increase exponentially. This was implemented in the Difficulty Bomb, the code for which wasn't changed as part of the hard fork.
That's not to say, however, that changes to this code won't be made in the future, before mining gets too difficult, either because the community isn't ready to move over to PoS, or for some other reason.