Wikipedia/MediaWiki Documentation and the GFDL

I've been reading around a little bit more on some of the other  
MediaWiki-powered websites that are out there, since I've been starting  
a new wiki with a few other people for "Star Trek"-related topics,  
Memory Alpha.  So far, we've frequently been copying the documentation  
pages from Wikipedia (for example, [[Wikipedia:Help]] and  
[[Wikipedia:How_to_start_a_page]]) -- and we've kept the proper  
attributions, of course!

However, after some discussion among ourselves and with a couple of  
Wikipedia contributors on the side, we decided a month or so ago to  
convert Memory Alpha to a Creative Commons License instead.  It was my  
understanding that this was compatible with the Wikipedia GFDL, but  
then I read a WikiTravel page which suggests otherwise  
(http://www.wikitravel.org/en/article/Wikitravel: 
Why_Wikitravel_isn%27t_GFDL).

What options are currently available, or could be made available, given  
the current Wikipedia copyright and the probability of other  
MediaWiki-powered websites using different copyright licenses but  
wishing to use the same documentation as far as the site's  
functionality is concerned?

(I apologize if this isn't entirely the proper mailing list to post  
this message on, but I feel it could/should be addressed here because  
it's a good idea to provide some documentation that can be available  
for everyone who uses the software -- and you guys make the software!)

Thanks,
Dan Carlson, Administrator
Memory Alpha: A Star Trek WikiWiki
http://memoryalpha.st-minutiae.com/