google is also behind v8.

you're free to do any choice you want... but this reasoning seems flawed to me: Go and Dart are open source and written by Google V8 is open source and written by Google

maybe you meant: "I don't know if Dart will be maintained in the long term, so I'll avoid it for now"

OT: I don't know what you mean by "left behind". Google uses Go for big sites like youtube: http://talks.golang.org/2012/splash.slide#70

Also, on some of my benchmarks, Go is faster than some other compiled languages (like D) and can be more memory efficient than Java: http://benchmarksgame.alioth.debian.org/u32/benchmark.php?te...

It's certainly not being "left behind", it's just new.

The main developer behind V8 is now the co-developer of Dart: Lars Bak