The 5 guiding principals of Enterprise Architecture - This is right on the money from my experiences of doing Enterprise Architecture:
No Strategic Vison, No EA:
If you know where you are, but you don't know where to go. Don't plan a journey.
Good is Good Enough:
An Enterprise Architect knows he has achieved the perfect solution not when there is nothing left to add, but when there is nothing left to take away.
The Only Constant is Dynamics: Dynamics is the only constant while adaptiveness is the natural variable, so plan for this constant.
Pure Logic is the ruin of the Spirit:
Pure logic is the ruin of the spirit and creativity delivers unexpected opportunities, so use your creativity.
Be Enterprising: If you want to create an Enterprise Architecture, don't drum up the architects to collect information and don't assign them tasks and work, but rather teach them to long for the endless value creating possibilities of the enterprise.