Per [1] As of 18th December, a majority of cases testing with the SGTF (indicator for Omicron) reached over 50% on the 14th December. It's clearer to see in Figure 2.
I have a strong feeling that current hospital cases are mostly delta ( there is a delay between both normally, since delta averages 8,5 days in hospitalization)
Even when new cases could be Omicron.
Either way, we will know soon.