[TextMate] Updating TextMate?

[bongoman]

As I slowly customise TextMate by altering the bundles in
~/Library/Application Support/TextMate, I'm wondering what happens
when TextMate is updated with alterations to the default snippets,
macros & commands?

To get the benefit of such bundle updates am I going to have to
manually edit my bundles in the above location to include the extras
in the new bundles? Or do the bundles in the actual application
package have effect to the extent that individual elements therein
have not been overriden by anything in the user's Library/Application
Support directory?

I hope this question is clear...

bongoman