If Apple were to only include full support on new devices, it would feel the wrath of the entire tech press, not to mention organizations like Consumer Reports and Greenpeace.
Not really, no. For example, h264 is hardware-accelerated on newer Macs (nVidia 320M / 330M), but not on the "old" nVidia 8600M-based Macs. The technical requirements are met (a 8600M is more powerful than a 320M), but Apple just won't release codecs.
The point is that no one important is apparently objecting to lack of Apple back-support even when it's something something (relatively) simple like an x86 driver update for (relatively) expensive Mac hardware. There is no evidence they would take offense at lack of a firmware upgrade for comparatively cheaper iOS devices.
There's a world of difference between playing h.264 in software on an older mac and what playing WebM in software (or not at all) would do to iOS devices.
h.264 and WebM are similar enough that it depends entirely on the implementation details of a "hardware decoder" as to whether it can handle one or both. Not all hardware decoders simply take in an h.264 bitstream and emit uncompressed a/v signals. Many "hardware" solutions are just a collection of execution units that handle the most time-consuming stages of decoding or encoding, and they are strung together with software and possibly use of GPU shaders to form a complete pipeline. For such devices, it may be possible to use them to accelerate WebM with most stages going through the fixed-function units and just a few things like entropy coding handled with compute shaders. Such a solution would be just as deserving of the "hardware accelerated" moniker as most of the decoding engines currently out there.
Yeah, I wasn't very clear in my first post. What I was getting at is that it is hardware that you can't reconfigure on the fly, which means you would have to choose between h.264 or WebM, you can't have both. For the next few years at least, the choice is clearly going to be for h.264, not webm
That dedicated hardware has no specific circuits with hardcoded decoding of specific formats. It is DSP with microcode and that microcode can be changed by updates.
Not really, no. For example, h264 is hardware-accelerated on newer Macs (nVidia 320M / 330M), but not on the "old" nVidia 8600M-based Macs. The technical requirements are met (a 8600M is more powerful than a 320M), but Apple just won't release codecs.