The question is what they are and whether anyone will still care once AMD Zen 3 CPUs arrive. There are three possibilities that I find plausible:
1) Rocket Lake is Sky Lake Refresh Refresh Refresh Refresh Refresh.
2) Rocket Lake is Willow Cove cores (Ice Lake/Tiger Lake) backported to 14 nm.
3) Rocket Lake is a desktop version of Tiger Lake.
Option (3) would probably be the most interesting, but Internet speculation seems to regard it as the least likely option. Rumors say that 10 nm yields and volume are still terrible, which is why Ice Lake is so expensive as to make itself basically irrelevant.
Option (1) may be mildly interesting if it brings a price cut, but considering that the MSRP price cut of Comet Lake seems to have only partially materialized in retail prices, it's not clear just how interesting another MSRP price cut would be. And if they try to push a little bit higher clock speeds at the expense of even more power consumption, that will bring a worse degree of the same drawbacks as Comet Lake.
Option (2) would probably be unprecedented in the history of consumer CPUs (or GPUs, for that matter), but then again, so are Intel's 10 nm struggles. That could bring a considerable IPC boost, but would likely come at the expense of clock speed. Even so, if it can get more performance than Comet Lake with less power, that would be a welcome improvement.
Intel did promise that Rocket Lake will bring PCI Express 4.0. That isn't really that important, but it's good to finally see it. Remember that AMD had PCI Express 4.0 in mid-2019.