I wonder if I might help out KH, who knows lots more about boats than me, but praps is evidently less experienced in the choppy waters of bulls*%#ting the users regarding forthcoming home-cooked software. This is especially difficult if you aren't or can't do the programming, but are to blame.

1. It is unwise for you to ever promise that the new version will do anything other than actually have a new version number. Limit your promises to specific things such as "it will do this". Do not promise that it'll be better because you'll find that half the users like the bit that you thought was a bug.

2. You should increase version numbers a little (from say 2.11 to 2.12) if it's a wholesale rewrite and you want to pretend otherwise, and of course increase version numbers in huge leaps (from say 2.11 to 2000) when sod all has been done, other than of course, change the version number. As software boss, you decide the version numbers.

3. Programmers will be developing at least two new versions going at the same time - the new one, and the one after that. This looks really industrious, and the software boss is really pleased that he's got such an ace team and may be lured into making announcements as you have done. However, having version 4 on the point of launch, whilst already talking of version 5 gives them a drop zone for hard bits (they'll go in version 5 of course) and an excuse for version 4 eventually being a bit manky, namely that their minds are now on version 5.