Taxonomy/Views related questions: custom "menu" and count of descendant products

Hey all. I've come across a couple snags that I'm hoping for some help with.

First of all, I'm able to get a count of all children nodes of a term by using taxonomy_get_children() (http://api.drupal.org/api/function/taxonomy_get_children/5), but is there a library function (or some other means) to get a count of all descendants of a term? I have a multi-level taxonomy hierarchy, and, in general, all nodes are tagged with a single term at the deepest level.

Secondly, I have a custom, argument-based view that I've created (products/$arg) that displays all nodes tagged with a term equal to the argument. In one of my block areas, I have a block that outputs all terms in this particular vocabulary and a link to the appropriate page:

<?php
            // The ID of the taxonomy vocabulary for which you'd like to create a nested list
            $vid = 1;

            $depth = 0;
            $num_at_depth = 0;
            $tree = taxonomy_get_tree($vid);

            print "<ul class=\"menu\">\n<li>";
            foreach ($tree as $term) {
            $diffdepth=0;
              if ($term->depth > $depth) {
                print "\n<ul>\n<li>";
                $depth = $term->depth;
                    $num_at_depth = 0;
              }
              if ($term->depth < $depth) {
                $diffdepth= $depth -$term->depth;
                while ($diffdepth > 0){
                    print "</li>\n</ul>\n";
                    $diffdepth -- ;
                }
                    $depth = $term->depth;
              }
              if (($term->depth == $depth) && ($num_at_depth > 0)) {
                  print "</li>\n<li>";
                }
$termPath = strtolower($term->name);
$termPath = str_replace(" ", "-", $termPath);  
              print l($term->name, 'products/' . $termPath);
                $num_at_depth ++;
            }
            print "</li>\n</ul>\n";
?>

Is there any way to get the block to "interact" with the views pages that are created? That is, if someone visits products/term-A (where Term A is a child of Term 1), the menu currently looks like this and does not change for all views:

-Term 1
--Term A
--Term B
--Term C
-Term 2
--Term D
--Term E
-Term 3
--Term F

I'd like the menu to look something like this when someone was on products/term-A, products/term-B, or products/term-1:
-Term 1
--Term A
--Term B
-Term 2
-Term 3

I'm stumped because there isn't really a strong relationship between the view itself and the menu, and I'm not quite sure where to start.

Thoughts?