This suggestion is important to big boards and anyone hoping/expecting their site's traffic to grow.
With the introduction of the CMS and focusing more on media* this software is going to need greater support for multi-server installations. I'm not talking about support for sub-domains via URL rewriting. I mean splitting entire websites across several physical servers.
The software will eventually need to be able to scale for setups like this:
Database server
Webserver for forum php files
Webserver for CMS php files
Webserver for static files
Webserver for uploading & downloading attachments
In some larger installations we'll need to do load balancing on top of that.
The important points that I hope get addressed will be offsetting the static files to another server (in particular there needs to be an option to store all thumbnails as static files) and making provisions to use another server for media files.