Given that I have an Apple TV (or a few) and a Roku (or a few), the fact that I can stream NetFlix on the Chromecast is of limited value to me.
What makes it worth the $35 (or, for those of us who got in early, the effective cost of $11) to me is the ability to access Google Play content. Access via Nexus devices is a breeze, and access via Chrome isn't too bad either. I've not tried with an iPhone/iPad yet.
I wish they'd have put the micro USB port somewhere other than the end, because it just makes the whole thing too long to comfortable hide behind a lot of TVs, and I wish they didn't add the bright white LED, and I wish they did 5GHz. But that can come in the next generation. A $35 streaming device for Play content makes me very happy, and the fact that I can set up an ad hoc network and stream to hotel room TVs and such makes it even better.
Overall, I'm extremely happy with the device and with the incredible ease of setup. That said, it's there for Play Content. Pretty much anything else will likely still go through the other devices... although I must admit that the ease of getting Netflix content on the screen is pretty compelling.