Add parent taxonomy weight to sort criteria

It would be ideal if the parent taxonomy weight could be used in conjunction with the taxonomy weight for sorting. I've been testing this patch: http://drupal.org/node/817536 (which adds fields for the parent taxonomy terms), and everything seems to work without a problem. I just wish I could sort on the parent's weight, then the child's weight.

This feature, in conjunction with the patch above would allow me to sort and display my nodes as follows:

2011
    December
        Node 1
        Node 2
    November
        Node 3
    ...
2010
    December
        Node 100
        Node 200
    November
        ...