We have all been left in the dark about this. Originally it was said to be Easter but that was almost half a year ago now. Judging by the fact more distributors are selling the Vision Kit (for example recently Adafruit), the next stage should be getting them to the UK. Wouldn't be surprised if Pimoroni or another UK Pi Shop are in contact with Google over this. It's possible they are already on their way over (I doubt it though).
I got a bit excited about the Edge TPU and USB then I realised us people in the UK probably won't get it for years!