Nodes associated with taxonomy terms are not tagged with the term

Issue Summary

This bug is related to Patch to add tabbed user interface and other enhancements.

I notice that when you select the content type that a taxonomy vocabulary should correspond to, the Taxonomy Node module forces that content type to be included in the list of content types that the vocabulary applies to. That somewhat makes sense, since the nodes being created do pertain to each term in the vocabulary. What doesn't make sense is that the nodes aren't actually *assigned* to their corresponding taxonomy terms.

Consider the following steps:
1. Create a taxonomy vocabulary called "Audiences".
2. Add terms to the "Audiences" vocabulary.
3. Create a content type called "Audience Descriptions".
4. Set the "Audiences" vocabulary to use "Audience Descriptions" for Taxonomy Nodes, and enable "bulk creation" of nodes so that all the terms created in step 2 get associated nodes.
5. Open one of the nodes generated in the previous step and look at the disabled taxonomy field.

Expected Behavior:
The selected taxonomy term should be the one that the node corresponds to, and the field should not be editable.

Actual Behavior:
The field is not editable, but nothing is selected.

In taxonomynode_form_alter, around line 267, if you print out the value of $form['taxonomy'][$vid], you'll see that it has no default value, which I believe means that the node has no taxonomy assigned.