They will come to MacBooks (and other mainstream platforms) if and when there is a user-centric utility to them and they can be integrated painlessly and economically.<p>Ignoring the latter criterion, GPUs are integrated because they benefit the typical user experience by enabling high-end graphics and have the side benefit of providing an alternative mode of computation that can benefit some restricted use cases required by some users. TPMs will need to fall into a similar use-case before they are even considered for inclusion.<p>There's loads of very flexible, useful hardware types that have been around for ages and are not included (general-purpose DSPs, FPGAs, SDRs, <i>& cetera</i>) because despite being useful for some things done by a few users, there simply isn't a reason to make them default.