>From personal experience in Taiwan, I found it enormously helpful to be
able to meet other Wikimedians from so many different places. (Japan,
Taiwan, Australia, India, the Middle East, Europe, Canada, the U.S.,
and many other places) As well, there are positive benefits of
cultural exchange, and outreach to Egypt and other nearby countries
also has positive benefits.
There will always be a certain percentage of attendees that are from the local country or region, who otherwise will not attend. As mentioned already, for whatever reasons, the Arabic Wikipedia is still small (compared to the number of speakers of the language). This is an excellent opportunity to outreach to them and grow the community.
Then in 2009, we will have Wikimania in another place (maybe Atlanta or Toronto?), which will draw different people from the local region. Though, I'm sure there will be people from Taiwan and Egypt who will continue to come to Wikimania, regardless of where it is. In my experience of organizing conferences, I find this to be the case.
-Aude