In both "La Vita È Bella" (Life Is Beautiful; Italian) and "Central do
Brasil" (Central Station; Brazilian), the main female character is
name Dora and the young boy is named Giosué and Josué, respectively
(Joshua in English).  Is there any significance or is it pure
coincidence?

Hi, Nelson!

This doesn't answer your question, but I thought you might find it interesting.

From a review of "Central Station":

"One should not, by the way, make too much of names such as Josue
(Joshua) and Jesus, the elusive father, nor the fact that Jesus is a
sort of carpenter. Symbolism may be present , but with a light touch.
Curiously, in the other main candidate for Best Foreign Film Oscar
this year ( Life is Beautiful) the woman is called Dora and the child
is Josue..."

http://www.prairienet.org/ejahiel/central_station.htm

From an article about "Life Is Beautiful":

"Giosuè/Joshua/Yeshua is not only the name of the prophet of the sixth
book in the Old Testament. It is also the Jewish name for Jesus. In
the film, Giosuè materializes suddenly, halfway through, as the
product of the fabulous love story between Dora and Guido. I am not
suggesting that Joshua is a Christ figure. If we remember, however,
that Christians, and Italian Catholics especially, have the bad habit
of forgetting Jesus' Jewishness, we may appreciate this additional
ramification of the son's name, indeed a reminder to all Italians that
their 'cultural hero' is in fact the Other, someone they themselves
persecuted (while blaming the Jewish Other for it)."

http://216.239.41.104/search?q=cache:98AL1Xli1MIJ:www.metrostate.edu/cgi-bin/troxy/lproxy.cgi/URL-www.press.jhu.edu/journals/jewish_social_studies/v005/5.3viano.html

Thanks, pinkfreud.  Interesting info., although, as you stated, does
not answer the question.