The highlights include turbo speeds of at least 5 GHz, single-threaded performance increases of at least 15%, PCI Express 5.0 support for both a video card and an SSD, DDR5 support, and an integrated GPU in the I/O die.
That the parts used for the single-threaded performance increase are unspecified makes the claim meaningless, though AMD hasn't normally been aggressive about cherry-picking corner cases to make wildly inflated claims, so it's likely to be more or less accurate. It sounds like much of the gain will come from higher clock speeds.
The new AM5 socket will support up to 170 W, which likely means that Zen 4 parts will have a turbo power of 170 W, up from the current 142 W for Zen 3 parts. More performance coming at the expense of more power seems to be a common theme in computer parts in recent years, though at least 170 W would remain far below the 241 W of Alder Lake.
The CPU core chiplets move from TSMC 7 nm to 5 nm. AMD claims that the L2 cache per core doubles to 1 MB, though they didn't say anything about L3 cache.
The I/O die moves from Global Foundries 14 nm to TSMC 6 nm. An I/O-heavy chip can have its minimum size dictated by the need to have enough space for pins for the I/O. It's possible that that left AMD with a bunch of free transistor space to use, so they decided to put in an integrated GPU. It's also possible that it's a very small integrated GPU with only two or three compute units or some such, which is still plenty enough to display the desktop. We'll learn more about the chip when it launches in several months.
Zen 4 parts will be DDR5 only. That's in contrast to Intel's strategy for Alder Lake offering both DDR4 and DDR5 support. The more time passes, the less need there is for DDR4 support, and it's likely that Intel's next generation won't support DDR4, either.