Not really for servers
Ladd said there is growing interest in using Dart for server-side applications…
Not sure if that's really got legs. Sure, people are bound to want to try language X on both client and server (node.js being the most prominent example) but the environments often have different and even contradictory requirements.
Having looked briefly at Dart's syntax I've decided I'm more interested in how Go propagates from systems work to applications. Yes, I know that's a non-sequitur but Go just seems more innovative as a language and has a less antiquated syntax.