So much of how employees (myself included) are evaluated is based on
performance relative to goals. And that, of course, makes those goals
pretty darn important.

Some thoughts on this from a truly interesting essay on goal setting as it relates to progress discovered via Bblog:

There’s
  two parts to defining progress. The first is in planning the work and outlining
  a set of goals the work is supposed to achieve. If I told you to put out the trash,
  and pointed you to 3 full trash cans and a street with a signpost that said “put
  trash cans here”, it’d be clear to you what progress looked like.
  Even with complex work, the goal of a leader is the same: you want everyone to
  know how the world should be like when they’re done. Then they can compare
  what they’re doing today with the goal and make adjustments. This vision of completion
  can change, but everyone’s vision should change together (and it’s the leaders
  job to make that happen). If there is no vision, the first goal leaders set can
  be for everyone to contribute ideas for the vision.