My take on beta 10 and the promise of a public fsd beta:
1) Beta 10's visualization will likely be based on the spatial RNN mapping that Karpathy mentioned during AI day. This means that the car will paint a more stable map of it's environment based on its confidence of the road geometry and features. With V9, the visualization is continually updated, so the NN is redrawing the visualization with every frame. With beta 10, the car will only draw what it's confident of, and the map is persisted after the car drives past the road geometry. The car will only overwrite a pixel if its confidence increases in subsequent frames.
2) Tesla's NNs are always completely retrained whenever they want to include a new or updated dataset. Karpathy even said so during AI day when asked about "continual learning" during Q&A. So what's Elon talking about when he says Tesla is retraining the NN? I think he's just saying that Tesla has updated their NN architecture, and it now needs to be retrained with the existing dataset.
3) How does Elon know beta 10 is next level if he's only driving 9.3? It's likely beta 10's NN has gone through several shadow modes, so it's getting to the point where it's ready, and they can see from the outputs of the shadow mode NNs that it's "next-level." We know this is the case because Elon has mentioned beta 10 for a while now, but the Tesla team didn't know exactly how many shadow builds it required to reach their deployment threshold.
4) It's still very unlikely The Button will be available in 4 weeks...
5) This is all my speculation. We can confirm once it's released soon.