Once you remove the limb from the host, so to speak, you've negated much of the benefit.

Simple web traversal and archival will preserve links, though they become static.

The InterWikis plugin allows you to reference (statically) a topic in another TWiki, which is another mode of extraction/syndication. Having just added the RDF headlines grabber to [link|http://twiki.iwethey.org/twiki/bin/view/Main/|TWikIWeThey], I'm now thinking of some sort of RDF export to allow people to remotely check the most recently updated topics. Hmm....I think that's readily doable with a search, 'coz that's all it is.... ;-) Will mess with that shortly.

So, point being: yes, you can export content readily. However, you're going to lose some of the context, including the live linkage, search, etc. Overall though, not a bad bargain.