[stevenameyer]

The one thing I would give as a benefit to setting a deadline is that it can help prevent feature creep for a specific version.[0] The amount of times that I have had a manager come to me just prior to a version being ready to ship and ask me to squeeze a new feature into this release is staggering. This is where being able to push back with "not if we are going to hit the release date." really helps.

Now ideally you are able to agree on what to put in each release and stick to it, but a lot of work places are not ideal and feature creep can be a huge issue which can easily be addressed by implementing a release schedule and sticking to it (for the most part).

[0]This is more applicable to areas such as mobile where it is unrealistic to ship releases every week.

[zinssmeister]

feature creep would be a good topic for another blog post some day... met many of those.