The $35 (about £22, AU$38) accessory was revealed alongside Android 4.3 and the new Nexus 7 tablet on Wednesday. It lets owners stream content from their smartphone, tablet or computer to a HDTV via the Cast app.
Those who already own most Google TV-compatible devices won't need the dongle once Google has retrofitted its Smart TV platform with the same streaming tech with a forthcoming Jelly Bean update.
Responding to speculation and questions that Chromecast would kill Google TV, staffer Warren Rehman wrote on Google+: "I'm still gainfully employed working on Google TV - no it isn't dead, and yes it will support Cast."
Why buy both?
In replying to further questions, Rehman clarified that all ARM-based Google TV devices updated to the forthcoming version of Jelly Bean 4.3 would support Chromecast.
He said the company is "putting the finishing touches" on that update, but didn't specify when it would hit Google TV devices.
He also responded to questions from commenters asking 'why bother with Google TV?' when Chromecast is available so cheaply.
He wrote: the "Chromecast is Chrome OS-based and does not natively run Android apps whereas the Google TV devices are Android based and do natively run Android apps. Also, there's the whole 'live TV integration' which Chromecast doesn't do and Google TV devices do do."
Chromecast was well received following its announcement, with consumers stateside snapping up pre-order stocks with a quickness.
It gives Google a chance to match Apple's excellent AirPlay platform, which allows Mac and iOS users to quickly push entertainment content to their Apple TV set-top boxes.
- Want to learn what devices are due to get Android 4.3? We've got the 411 for you right here.