UPDATE 6:54PM PDT:
Aaaand we're down again.
UPDATE 5:54PM PDT: All issues should be resolved at this time. *wipes sweat off brow* What a day! Apologies for the excitement, everyone.
UPDATE 3:57PM PDT: It appears that this issue may also affect patching the KR client, as well.
UPDATE 3:50PM PDT: It worked for a little while; we're getting reports of login issues again with the West Coast servers. Investigating!
UPDATE 3:18PM PDT: The network issue with the west coast servers should be resolved. Thanks for your patience!
UPDATE 3:03PM PDT: We believe we've narrowed down the problem and are working on a solution. Stay tuned!
Many people are reporting that they can't log in to shards on the West Coast (for a list of shard physical locations, click here)
We're investigating, and will post updates as we get them.