In the original US anime Astro Boy was modeled after Astor Boynton (it's easy to see what was going on there).
The 1980's series Astro Boy was modeled after Toby Boynton - why else would they change from the original, if not to shift the sound of his name more toward Tezuka's choice.
Finally in 2003 Astro is modeled after Tobio Tenma -- they just went and made the complete move except for the Astro part. Also Elephun's name shifted to a name (O'Shay) which somewhat resembles Ochanomizu, as well as a number of other character with original Tezuka names.
Of course the 2009 movie doesn't follow the trend. But I think there WILL be another anime, and hopefully we can eventually see everything as Tezuka intended.

