I've used the revised Bloom's taxonomy as a reference tool frequently in my role as an instructional designer. I agree partly with the discussion so far, Bloom's taxonomy is not a learning theory, or a learning model, nor is it stepped or tiered approach, [each level building on the other]. Did Bloom plan it to be tiered or was this incorporated at a later date? I am not sure, but reading the reference from the link provided by Romi, it appears this tiered concept was added later.

I use Bloom's in several ways: 1) as mentioned in the article, as a reference tool when collaborating with other educators - to use a common language. The domains serve as a framework when planning learning activities and assessments in curriculum. For example when designing an assessment tool for a given module of a course, "should we use a multiple choice test to confirm student comprehension (understanding), or are we wanting the student to be engaging critical thinking skills, which would require the student to analyze what he or she learned, perhaps write and essay, and draw comparisons to other concepts and incorporate previous lessons materials".

2) As a tool to write instructional objectives, which drives the learning activities and assignments. Here is a link providing an overview of this function: http://sociallearningsystems.typepad.com/home/2009/07/tips-for-writing-instructional-objectives-blooms-taxonomy-job-aids.html

Interesting and thought provoking discussion, thank you. Debbie