The first change is in appearance. The black dongle hardware will be replaced by a circular-shaped device available in three colors, according to the report.
The second generation Chromecast will have a new feature called "Fast Play," which aims to "cast" content much more quickly and seamlessly than the current version.
Improved wi-fi and support for content feeds on the Chromecast home screen are also expected, according to 9to5Google.
This might mean social media feeds or image feeds can play when your Chromecast is in its screensaver mode.
The report also says Google will announce Spotify is preparing to launch Chromecast support in its mobile app.
As with any report that's not directly from a company, we'll have to wait to hear it from Google itself at its September 29 event.
In response to a request from CNBC, Google said it doesn't comment on rumor or speculation.