Even in XP there are things you need up front. These include:

	* Appropriate tools to the problem domain.
	* A team skilled with those, and willing and able to go XP.
	* Customers willing to commit time to their involvement in the process.
	* A SystemMetaphor.
	* StarUnit and an SCM appropriate for your tools.
	* At least one satisfactory SpikeSolution.
	* An initial CommitmentSchedule full of UserStories.

All these things are architectural.