This is awesome
They've created RNA that can replicate itself indefinitely, and with replication, also comes evolution, and they've already seen evidence of the most fit RNA molecules taking over the petri dish. It's not quite life yet, but its close and it's getting there. We've been close for a while so this isn't groundbreaking in theory, but being able to actually accomplish it in practice is HUGE.
RNA is huge because it is theorized that all life started out as RNA (RNA World hypothesis). RNA is an interesting molecule because it is capable of acting both as a carrier of genetic information, and as catalysts for chemical reactions (e.g, enzymes). In our bodies, DNA generally stores our genetic information, and proteins do the work, with RNA as a mediator in between. DNA is generally found as a double helix, while RNA can form double helix, it is frequently just a single strand, and it can manipulate itself into different three dimensional structures, giving it different functions like a protein has (a protein's function is determined by its three dimensional structure).