The Toyota Altezza was the name of a Japan-market sedan that was later exported to the USA and rest of the world as the Lexus IS, with a bunch of different engine choices.

Pretty much the whole Lexus lineup as we know it is some kind of Toyota in Japan. The LS430 is the Celsior, SC430 is the Soarer, and the ES330 is the Windom. SUV-wise the LX470 is the Land Cruiser Cygnus, the GX470 is the Land Cruiser Prado, the RX330 is the Harrier.

Now the previous two generations of the Lexus GS have been sold in Japan as the Toyota Aristo, but the Toyota Aristo has been discontinued. The Lexus GS has, I believe, already been shown at the Tokyo auto show as a Lexus rather than a Toyota Aristo, and is going to be the first car sold as a Lexus in Japan. It's also worth noting that the new GS shares its mechanicals with a car that's been out in Japan for a while now, the Crown Athlete.

I believe that as Lexus rolls out new models, they will become Lexuses (Lexii?) in Japan and their JDM Toyota counterparts will fade away. So in that sense, perhaps the Altezza is the next one up on the chopping block, because the IS is the next Lexus to be introduced after the GS. Who knows.