for continuous integration as in build server, I'd use Jenkins; for network-wide configuration management (which I think is what you were asking), Salt
As someone about to start architecting their first reasonably sized deployment automation project, what do you think one should be using instead? (Currently planning on Chef.)
Depends what you're deploying. I use a lot of puppet to deploy openstack, which means interacting heavily with community modules for things like mysql and rabbitmq. The situation will be identical for Chef (but replace 'module' with 'recipe)'. If you are primarily deploying software for which there are mature modules or recipes, I think choosing salt or ansible is more likely to result in you having to patch the upstream modules than puppet or chef.
If you elect to go with puppet or chef, be prepared to use something as an orchestration tool compliment the configuration management. Ansible and Salt can both be used as orchestrators to compliment a puppet or chef based configuration.
Of course, if you're deploying something simple, it makes no difference what you use. They will all handle package installs, config file templating and service management. In this case, Ansible/Salt are probably better as they will contain the orchestration features.