Haven't tested this, but the upload function of the Market tells you in this case something like:
The version of the App that you are uploading is available for less devices than the previous version that you've published. Users of devices that are not supported by your latest version will therefore not get an update. So I'd guess Android 1.6 users will simply not receive your latest version, nor will they be notified of the update. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en