The network can be viewed here: https://lnmainnet.gaben.win/ - at the time of writing there are 65 nodes and 125 channels currently open!
It hasn’t ‘officially’ launched - however brave individuals have gone ahead and started the network anyway.
This is so exciting! It’s like watching the birth of the internet. It’s mostly in a ‘testing / experimental’ phase, but it is live. It’s actually a pretty interesting situation right now - as users are potentially risking their Bitcoin if there are any bugs in the protocol. On the positive side, it also means that if there are any potential exploits it would hopefully be discovered sooner rather than later.
This may potentially have had some impact on the recent sudden spike in Bitcoin’s price, as well as potentially the drop of altcoins (relative to Bitcoin).