It's TPM for ARM, basically.
But, more interesting, is that this will never be the "only" device that such content is available on. As another caveat of the "analogue hole" method, if there's a single, unprotected (or poorly protected) 1080p digital content source out there, then all the rest don't really matter. Who's going to hack the 1080p on their smartphone (why 1080p on a smartphone anyway?) when they can just take the content from somewhere else?
The thing about copyright infringement is: the original copyright infringers don't really care where the content has come from, and aren't the majority of your consumers. If anything, they are the tiniest, tiniest minority for whom even these sorts of measures aren't show-stoppers (see the linked article about the TrustZone compromises, for example - not saying that guy did it for copyright infringement, but there are people just that clever all over the net). Once a single, unlocked, digital content source exists, then a million people can copy the movie. It's that SINGLE copy ever coming about that you have to stop (without alienating your existing customers), not the casual smartphone user.
And moving EVERYTHING to TPM, across all media, formats and manufacturers, is going to be a bit of an uphill struggle (consumers? Pah, they're happy to pay/rent on the contractual bases that already exist, for the most part, and might not like but generally tolerate things like "on X amount of devices only", etc.). For a start, it means the end of all DVD / Blu-ray -type formats, and that no one manufacturer ever makes a mistake (and, in fact, the TrustZone hack linked actually uses the Linux source code and some poor security in the code to compromise the device - which means that ANY NUMBER of similar devices might well be running that kind of code already).
It's the next logical step in the TPM evolution. The problem is that it STILL doesn't stop "piracy". Hell, if it came to it, I'd just tap into the stream going to the LCD. Sure, it's awkward but it would work and obtain full 1080p 60fps perfect digital copies. It would mean raw frame captures (and thus recompressing them back into something MPEG-like) but that's a small price to pay if you're that determined. And once ONE guy has done it, that's game over for that content.
I'd still place bets that the more profitable venture over the next decade or so would be to just sell un-DRM'd (but maybe tagged in some way, e.g. with steganographic subscriber name/numbers etc.) plain content for a decent price. But without something like that existing it's hard to prove that would be the case. I think things like Amazon MP3, though, kinda already proved that it would work without bringing an industry to its knees.