COVID mRNA vaccines can be quickly updated for new variants. So, where's my Omicron booster?

Since Omicron was declared a variant of concern at the end of November, it quickly swept the globe, becoming the dominant COVID variant in many countries including Australia. It's the latest in a growing line of variants, and probably not going to be the last. Yet every one of the hundreds of millions of approved mRNA vaccines administered around the globe were made to their original recipe, which was based on the COVID virus that first emerged in Wuhan. One of the most promising aspects of the new mRNA COVID vaccines is their ability to be rapidly adjusted for maximum protection in the face of new variants. So where's my Omicron booster?