I do not know the fate of the three websites listed below, but i understand how crucial it is to find a way to truly preserve such sites.
When the inevitable software update occurs, hopefully these sites will not lose their integrity or worse off, be lost in the ether never to be seen again. Given these sites are maintained on the National Geographic and Ancestry.com website, i do not believe running out of funds will lead to the demise of these sites. The backing of large and popular sites that a well maintained will certainly not hurt the longevity of these sites, but on the flip side that is no guarantee.
Having the user participation aspect, i believe these sites will last as long as their popularity lasts. That is as long as the number of participants contributing to the sites remain significant.
I really like the World Memory Project because there will never be a shortage of people interested in finding out about their ancestors and where they come from. That type of project could branch out into a much broader project. The Geneographic Project almost does that for the World Memory site, except through tapping into your DNA versus lost documents newly rediscovered.
I assume data collection for the Geneographic Project is quite extensive and archived or backed up in numerous digital formats and perhaps saved in some analog fashion as well. After all, it is said that paper copies should always be maintained. On another note, i wonder what they do with the samples they collect?