gistfile1.txt

es
version: 0.0.23
Missing template processorError: Missing template processor
    at module.exports.preprocessTemplates (/Users/adolfo/code/ember-cli/lib/preprocessors.js:44:11)
    at EmberApp.<anonymous> (/Users/adolfo/code/ember-cli/lib/broccoli/ember-app.js:83:25)
    at EmberApp.memoized [as appAndDependencies] (/Users/adolfo/code/ember-cli/node_modules/lodash-node/modern/functions/memoize.js:65:28)
    at EmberApp.<anonymous> (/Users/adolfo/code/ember-cli/lib/broccoli/ember-app.js:122:41)
    at EmberApp.memoized [as javascript] (/Users/adolfo/code/ember-cli/node_modules/lodash-node/modern/functions/memoize.js:65:28)
    at EmberApp.toArray (/Users/adolfo/code/ember-cli/lib/broccoli/ember-app.js:150:10)
    at EmberApp.<anonymous> (/Users/adolfo/code/ember-cli/lib/broccoli/ember-app.js:157:26)
    at EmberApp.memoized [as toTree] (/Users/adolfo/code/ember-cli/node_modules/lodash-node/modern/functions/memoize.js:65:28)
    at Object.<anonymous> (/Users/adolfo/code/sandbox/Brocfile.js:63:22)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.loadBrocfile (/Users/adolfo/code/ember-cli/node_modules/broccoli/lib/builder.js:101:14)
    at Task.module.exports.Task.run [as _run] (/Users/adolfo/code/ember-cli/lib/tasks/serve.js:13:28)
    at Task.run (/Users/adolfo/code/ember-cli/lib/task.js:25:15)
    at Command.module.exports.Command.run (/Users/adolfo/code/ember-cli/lib/commands/serve.js:21:36)
    at CLI.<anonymous> (/Users/adolfo/code/ember-cli/lib/cli/cli.js:21:36)
    at invokeCallback (/Users/adolfo/code/ember-cli/node_modules/rsvp/dist/commonjs/rsvp/promise.js:228:21)
    at publish (/Users/adolfo/code/ember-cli/node_modules/rsvp/dist/commonjs/rsvp/promise.js:176:9)
    at publishFulfillment (/Users/adolfo/code/ember-cli/node_modules/rsvp/dist/commonjs/rsvp/promise.js:312:5)
    at flush (/Users/adolfo/code/ember-cli/node_modules/rsvp/dist/commonjs/rsvp/asap.js:41:9)

Add the broccoli-ember-hbs-template-compiler package to your devDependencies.

I tried @dmathieu's suggestion and it stopped throwing the error for me but was not rendering the application template. Then I read through this announcement - http://emberjs.com/blog/2014/12/08/ember-1-9-0-released.html.
npm uninstall --save-dev broccoli-ember-hbs-template-compiler
npm install --save-dev ember-cli-htmlbars@0.6.0

fixed the problem for me.