Here's an updated table, with version numbers included and their status:

   Gemini Models     gemini.google.com
   ------------------------------------
   Gemini 1.0 Nano
   Gemini 1.0 Pro        -> Gemini (free)
   Gemini 1.0 Ultra      -> Gemini Advanced ($20/month)
   Gemini 1.5 Pro        -> announced on 2024-02-15 [1]
   Gemini 1.5 Ultra      -> no public announcements (assuming it's coming)
   

[1]: https://storage.googleapis.com/deepmind-media/gemini/gemini_...

For history of pre-Gemini models at Google, see: https://news.ycombinator.com/item?id=39304441