OpenAI celebrated ChatGPT's second anniversary in a big way a few weeks ago. The company held a massive "12 Days" press event, with each day bringing a new AI feature to various products. ChatGPT was a big focus and received various interesting upgrades in December, including a next-gen reasoning model (o3) that should see a wider release in the near future.
However, OpenAI did not announce an upgrade for the main model most people use. That's GPT-4o, which supports Advanced Voice Mode and multimodality.