PSA: The latest snapshots introduced a rather important packaging change for legacy (K2/DX/K3) hacks: instead of being split in per-model packages, there's only one for the whole set of devices. That makes for less confusing and much, much smaller archives.
The downside is that only
MRPI will be able to understand these packages.
If that's a deal-breaker, you can always repackage them yourself with KindleTool. For instance, given a package roughly named 'foo', and your target device being a WiFi K3:
Code:
kindletool convert update_foo.bin
kindletool create ota -d k3w update_foo_converted.tar.gz update_foo.bin
This new packaging layout is currently limited to the snapshots, but barring any uproar, that'll probably propagate to the next release packages too, because my time is much better spent doing interesting stuff rather than waiting for crap to finish uploading, and the legacy packages are rather beastly on that front

.