Is there a possibility that this will have a positive effect of a) pushing the issue to the forefront (because it affects everyone) where it can be easily disputed in its current form; b) making services like Tor / VPNs a necessity for regular people and thus moving everyone towards a safer internet not governed by states? This has already happened with the block of thepiratebay: regular people have been pushed into a position of regularly using VPNs.

Say Cameron get this passed. Technically it is unfeasible because they can't realistically ban foreign companies from using encryption, and because some of the protocols are (for the sake of argument) unbreakable. So if you want to stay anonymous, you still can, and more people will. Furthermore, the privacy argument goes mainstream when it is WhatsApp / Google vs. the UK government, with regular people suffering immediate consequences, vs. a bunch of programmers / cypherpunks. I can't see how this would be a positive for the government in any way.