The end of a development iteration should not be considered the final exam.
During a semester at college for a given class there were many assignments to be turned in, there were quizzes, mid-term exams, more assignments and quizzes, and the final exam.
When software development organizations adopt an iterative development process I have observed that the developers tend to over react to the iteration aspects of iterative development and forget about the full Product Plan.
New iterative teams seem to overreact to anything that might interfere with their "well-define" iteration. If you get to the end of your iteration (and I am thinking about one to two week iterations) and you got less done or you got more done it is okay. The end of an iteration should not be viewed as a "final exam" and should not carry that type of weight.
I believe that developers are afraid they will be judged on the results of the end of an iteration in the same manner they would be judged on the results of a product release. This should not be the case.
I believe that managers are afraid as well and some how feel they need to show that they can accurately predict software delivery after ten or fewer iterations of release schedule that is made up of fifty or more iterations.
I know of "agile" managers that refuse to add something to an iteration even if the developer got all of the other tasks done and there are two more days left. Is velocity really that precious? Is the manager's ability to sell up the idea that this manager can accurately predict and estimate software to such a fine degree really what is important?
There is an entire Project/Product plan. Features and enhancement are gathered. These are divided into releases that could cover several versions of the product over several years. Releases are divided into iterations. Iterations are quizzes.
Maybe there should be some type of "mid-term" exam where the current set of functionality is deployed to a test environment or a test installer just to see where things are at and that we are not forgetting something (like securing licenses to redistribute 3rd part components).
Lighten up on the end of iteration stress that is artificial and not needed.