Gradual silent upgrading is poised to be a huge problem for users and yet another reason I stay away from Chrome. You should never impose an upgrade on a user, at most just strongly suggest they install and make it easy if they choose to do so.
Upgrades have the potential to break things users may find critical. Say for example in a browser, User A uses a plug-in that they find essential to their daily work and it hasn't been updated to the latest release (developer is on a sabbatical roaming the world for 2 months). Now you force an upgrade to their machine and you break their plug-in leaving them with no recourse. This is only one slim example but it's potentially a huge issue. A couple years back a Windows auto-update once killed a client's server for 2 days until I could identify the culprit. There at least I had recourse to uninstall and reject the update, with something like Chrome I don't.
In a web app things don't inter-relate the same as they do on a local OS so it's mostly a non-issue outside of user experience. Forcing upgrades to locally installed software is just asking for trouble all around.
Upgrades have the potential to break things users may find critical. Say for example in a browser, User A uses a plug-in that they find essential to their daily work and it hasn't been updated to the latest release (developer is on a sabbatical roaming the world for 2 months). Now you force an upgrade to their machine and you break their plug-in leaving them with no recourse. This is only one slim example but it's potentially a huge issue. A couple years back a Windows auto-update once killed a client's server for 2 days until I could identify the culprit. There at least I had recourse to uninstall and reject the update, with something like Chrome I don't.
In a web app things don't inter-relate the same as they do on a local OS so it's mostly a non-issue outside of user experience. Forcing upgrades to locally installed software is just asking for trouble all around.