It's too early, really. You don't take an experiment, and say "This will replace our main, stable product." You keep investing in it on the side until either, i

It's too early, really. You don't take an experiment, and say "This will replace our main, stable product." You keep investing in it on the side until either, it's mature enough to make that decision, or it fails for some reason. At the moment there is plenty of steam behind Servo, and it's growing all the time. So an optimistic outlook is that it will mature, and have a chance of becoming a full-fledged product. However problems might prick up, maybe Rust isn't quite as good for this as they think, maybe the experimental parallel architecture doesn't fully pan out. You can only make these kinds of observations when you've implemented most, if not all of the features required for the final product.