Agile Software Development: A Risk to Overall User Experience?

Hope you all checked out Nielsen's latest article on 'Agile Software Development' and it's impact on overall user experience.

A similar statement has been made by Larry Constantine in his report "The Usability Challenge" published recently in which he said "the absence of any comprehensive overview of the entire architecture" is a shortcoming of nearly all techniques that are based on iterative expansion and refinement in small increments.

Is this really a emerging pattern and such approach risks undermining the concept of an integrated total user experience that can end up resembling a patchwork?

Any thoughts around the same or discussion threads for Nielsen's article....