Go 1.1 comes with some impressive performance optimizations, but there are more optimizations that can be done and there are already some great ideas discussed, like a Preemptive Scheduler.
Just see what performance related changes where already made since the Go 1.1 release last week:
• SSE-powered string/bytes compare: http://code.google.com/p/go/source/detail?r=b2f1f8cb2fcb7025...
• less allocations in the JSON package: http://code.google.com/p/go/source/detail?r=00d69aa6619e77d8...
• optimizations to malloc(): http://code.google.com/p/go/source/detail?r=0fe374e887455a57... and http://code.google.com/p/go/source/detail?r=931a7362e30c2139...
• optimized aeshash: http://code.google.com/p/go/source/detail?r=80c8a9f81e4816e0...
• faster x86 memmove: http://code.google.com/p/go/source/detail?r=4cb93e2900d0c748...
• less allocations in the buffered I/O package: http://code.google.com/p/go/source/detail?r=bce231eb0fdd4bbe...
• optimizations in the flate compression package: http://code.google.com/p/go/source/detail?r=bd653e485f1d9b5c...
• optimizations to the net/http package: http://code.google.com/p/go/source/detail?r=647f336edfe88a31... and http://code.google.com/p/go/source/detail?r=d1d76fc0ab6a33f1...
• integrated network poller for BSD: http://code.google.com/p/go/source/detail?r=9d60132d77847262...