It's possible to publish daily updates for your application on Google's Android Market, but I have an assumption that users don't like to get frequent updates. How can I determine when I should publish updates? Is there an optimum interval to balance between delivering new features and bug fixes while not upsetting my user base?
While there can't some general best frequency for updates, here are some factors that you should look at when making your decision:
In my personal opinion anything that improves something for the user is worth a release. Especially with automatic updates and potentially updates only on wifi this is not disrupting to users imho.
Of course other factors will influence your release schedule as well. E.g. if your marketing team is still stuck in the old release habit with lots of features you might need to accumulate some for a marketable release.
Or if you are working with a server side application you might be tied to it updating as well.
So overall the answer probably is "It depends;-)" but more often is better. E.g. also consider upgrades to websites/webapplications like gmail or twitter.. many of these get daily updates..