Such a great feature, and very innovative for Firefox. I this new feature will be helpful for use among friends and colleagues. But for anything meant to last any length of time we will still need anchor links, such as id=.

Let's say you've linked to a highlight of a section on a webpage. If the original author of that webpage updates the content (eg Wikipedia), then there's a chance that the highlight will break or refer to the wrong thing.

I think the strength of this feature is in the short-term. If I want a friend or colleague to see a section of a page, I can link straight to it, share it, and they can view it fairly immediately. But as time passes, I wonder how well these links will hold up.

Text fragment linking already works in the latest version of Firefox, although you'll need to install an extension like this one to create links.