Very shortly the first Major Update to Firefox 3 should start rolling out. Like any other update users should get notification within the next 24-48 hours. What it sooner? Go to Help, Check for Updates. Users will be presented with a screen similar this:
Keep in mind this updates is optional and you are presented with three choices:
- select Later if you don’t want to decide now; Firefox will ask again in 24 hours
- select Never if you don’t want to accept this upgrade offer; we might send you another offer again in the future, but it won’t be for several weeks or months
- select Get the new version to continue on with the upgrade process!
Also, as with any other Firefox update it is going to wrong a ‘background-check” on your add-ons and automatically disable any that are not supported in Firefox 3. In the event you do have incompatible add-ons you will see this screen instead:
Clicking on ‘Show List’ will display a screen showing the incompatible add-ons with an option to check for newer version
Source: Mozilla Developer’s News