The problem is as a developer, you're damned if you do and damned if you don't.
Say that the next release will be out on a particular day and you run into some last minute problems and miss the date, you're damned.
Say that the next release will be out 'by the end of summer' and people are on your back for the last few months of summer, demanding where it is and then ultimately, debating which hemisphere the developer meant, which month summer ends and even if he meant this year
Don't say anything and people are constantly asking when the next release is out and quickly get annoyed when there's more than 3 weeks between releases. Go more than 2 months and they start thinking the developer's pissed off to the Maldives and the project's been abandoned!
In short, the developer can't win. Whatever he says, it will get thrown back in his face at some point. The only way to hit targets spot on is to aim short for a release, knowing that you've got a spare 2 months development time over what you've said as the release date. Problem is people get annoyed at the lack of new content.
I tell ya, the life of a developer is nothing but stress, stress and people asking 'when's the next version out' - oh, and when's the 'arcade/gallery/blog/cms/* coming'.
* delete as appropriate or add your own pet feature.