I guess after a while Mobil decided to end confusion about "High mileage" name, because some of the new cars were and still require 10w-30. On mobil's website you can find a whole bunch of questions and aswers about 10w-30 and "high mileage" name. There is nothing special about this oil no matter how you call it. I suppose they wanted to call it high mileage for some reason. They didn't change formulation just put a new label.
Actually, this is kind of funny. Mobil claims that engine with their oil after 200k miles showed "virtually no wear." If person had been using 5w-30 and mobil recommends using 10w-30 after 75k miles that means that mobil 5w-30 does cause wear if you need heavier oil.
I was out "Autozoning" tonight and I saw a poster in the window for an M1 sale they were having and the 10W30 label said, "Multiple Car Formula." So, I am guessing if you see these bottles this is the newest version you can buy (if they actually did any formula changing).
Patman, right you are. Problem is, consumers are without much clue as to which one to buy. Another example: I was in a place a few weeks ago--big sports and auto chain--and they had a sale going on for Mobil1 five-quarts. $13-something US.
It was Tri-Syn. It sold out.