I've just seen yet another thread complaining about the new gradient tool, which is sad because a lot of people are potentially missing out on a much more powerful gradient tool when advised to select Classic Gradient in the Options Bar. Of course there are times when the simplicity of the Classic Tool is the right choice and I would love to toggle between them with a shortcut, which could be done if the New Gradient Tool was added to the Toolbar, like below.
People who use shortcuts probably never use the Paint Bucket Tool, so we could chose to disable its shortcut, and toggle between the two gradient tools with the G key. My UI mock up could do with a better icon for the New Gradient Tool, but I think you get the idea. There would need to be an indicatior in the Options Bar so we knew which tool was selected.