How do you get the tid from a taxonomy term page? I've got a component on a taxonomy term page and need to use the TID in it's preprocess function. 

How do I actually get the tid to save as a variable?
You can use menu_get_object():

$term = menu_get_object('taxonomy_term', 2);
if ($term) {
  $tid = $term-&gt;tid;
}