In Python 3, subprocess.Popen returns stdout as "bytes" rather than "string" so it seems reasonable that subprocess.getstatusoutput should do the same.

>>> subprocess.Popen(['dd if=/dev/random bs=1024 count=1'], shell=True, stdout=subprocess.PIPE).communicate()[0]
1+0 records in
1+0 records out
1024 bytes transferred in 0.000142 secs (7218432 bytes/sec)
b'\x11\xfb\xe1w ...

The problem is reproducible on 3.1 and py3k.

The attached patch for py3k (with a backport to 3.1) corrects getstatusoutput to return bytes.  It also includes a test case and updates the docs to show byte output.