I recently upgraded to 2.3
Yes, I know the people who do WP programming have a different idea of how categories should be used from mine. (I have more than 2000 categories, and use them to index all postings which I have left permanently available.) But there is something to be said for a software tool possessing flexibility of use.
I cannot imagine why anyone would take the time and trouble to eliminate the new category entry box (in the Write Post page, and it would be very helpful to me if the powers that be would be kind enough to put it back.
I feel sufficiently strongly about that this that If someone puts it back and then sends me a reasonable bill for consultative services, I will forward payment.