The latest nightly builds of Fx 3 have now added Plugins to the add-ons UI (which previously only contained Extensions and Themes). This allows users to enable and disable the installed plug-ins much easier than before. However as Percy points out on his article, there are a couple issue:
An option not currently implemented is a way to check for updates for the installed plugins. A periodic check for new, more stable and safer versions and automated updates would be a big step forward security-wise.
Then there’s the problem with plugins that involve more than one file. For example, QuickTime is split into five library files, each of them to handle a different file types subset. The Plugins page lists the plugin as many times as there are files and there’s currently no way to tell which one is related to what. Java is another popular plugin in the same situation but Mozilla is already evaluating options to address these cases.
An update feature is a must as there is really no easy way to know if you are running the most current version of a plugin. Currently users will need to do an about:plugins (which does not list the plugins in a user friendly way) check the version numbers of the currently installed plugins, then compare that to the current versions listed in the plugins section on addons.mozilla.org site. I have to think the main problem with trying to implement an update process is all the plugins are third party and outside the control of Mozilla.
The screenshot shows what Percy was describing with plugins that have more than one file associated with them. There is no way to tell which of the QuickTime dll files are associated with that particular entry. Of course this is just pulling the info from about:plugins, so it is a matter of the plugins developers to make changes to the plugin description. Again, this is something outside the control of Mozilla.
News Source: Mozilla Links