You basically only get one console window per console process on Windows. In theory you could do this with native code, but I doubt anyone has and exposed it in a node module. So, the simplest solution is to have multiple processes. The easiest way to do this would be to effectively pipe your logs through a file, assuming you have "tail" installed, or something like it (there's probably one written in node in npm), you can do something like this:
var logger1 = fs.createWriteStream('log1.txt');
var logger2 = fs.createWriteStream('log2.txt');
child_process.exec('start "Log 1" tail -f log1.txt');
child_process.exec('start "Log 2" tail -f log2.txt');
logger1.write('To the first!');
logger2.write('To the second!');
You can probably do something more complicated with actual pipes instead of files, and have the sub-processes be something like "type" or "cat" which exit automatically upon a broken pipe.