The developers will primarily be focused on getting coding and control implementation in place at this point. Getting an interface in place to setup the game will be a work in progress within each of the phases.
The mappers will be interested in getting textures and scenarios thought out. A test level will be designed to see if we can control a character, fight monsters, control parts of the environment, etc. The majority of the mappers interest is seeing if all the ingredients mix well or if the formula is off.
This phase will require the most intense interaction between teams. Individual deadlines will be set within this phase, requiring communication and patience.