https://covid.cdc.gov/covid-data-tracker
Omicron sub-lineage BA.2 is increasing in prevalence. Now with a national point estimate of 3.6% for the week ending February 5th. Still generally low levels.
It appears to have a growth advantage over the original Omicron strain.
As I mentioned before it doesn't have S-gene deletion, so S-gene target failure can't be used to detect it. However since the original Omicron strain generally has it, you can differentiate between the two by the change in S-gene target failure prevalence.
BA.2 shouldn't change the overall picture for this wave. Preliminary vaccine data is promising on effectiveness against BA.2 despite the different mutations.
There is a new sub-lineage of Omicron BA.1.1 as well that is in the US. This sub-lineage seems to also be more transmissible than the original Omicron strain. So BA.1.1 might compete with BA.2 for dominance in the US in the coming weeks, pushing out BA.1 (the original Omicron).