I'm learning Javascript just to make a web app. There is nothing hard about it, with lots of resources available. Already knowing Python & Ruby makes things easier for me.

But if people only need to know Python, then web apps will become that much easier to make. I think this is related to the trend for smaller/lighter companies.

More people will think small and make startups if you don't need to know as much to make good applications. Lowering the number of languages needed to make an application would be a significant step in that direction. And making that language Python, which many would agree is one of the easiest languages to learn, will make it that much easier.