Let me give you my perception of this issue.
As a user, I evaluate programs based on a few categories such as functionality, ease of use, serving the intended function, and supportability (is that a word?). One of the key factors behind supportability is whether or not the author is actively involved in the project. I do not require updates for a program, but a lack of updates gets me worried since it could indicate a lack of support should an issue arise.
Let's say I invest 80 dollars into a productivity tool. After using it for a few months, I notice that a bug occurs when I perform steps X, Y and Z. Now, I go to obtain support and hopefully a patch. This is when I find out the author no longer supports the product or has just given up on it. In my eyes, an update, even if only to post to the homepage every few weeks, shows that the product is still alive.
No software is perfect, and there are ALWAYS bugs to fix. Updates do not necessarily have to mean new features, but it could reflect additional bug fixes. This level of support is more preferred, in my eyes, than posting updates to an application by adding features just for the sake of adding them. Do we really need a spell checker in an application launcher and does a book collection manager really require a DVD ripper?
In the end, updates are a good thing if done for the right reasons. Adding features, just because, is the wrong way to go about it. Keep up with maintenance and patching of an application and add features as your users show a genuine interest for them, or as capability gaps are identified.