The Apache web server is the most popular web server used on the Internet. This indicates that a large proportion of all Internet-related system administrators have encountered and configured Apache before. According to netcraft (http://news.netcraft.com/archives/web_server_survey.html), Apache dominates the market place with over 60% of overall market share. The server is stable, secure, highly configurable, and proven to scale to even the most demanding and acidic environment imaginable. Urban folklore mentions reliable services forgotten and running on very antique computers only to be found wanting when major earthquakes hit.
Sakai is highly scalable, especially behind load balancers with or without Apache server(s) in front of the Tomcat server. Therefore, the need to deploy the web server as part of your infrastructure is a matter of taste. The advantages of deploying Apache normally outweigh the extra complexities of the configuration and any extra learning...