Marcio (as you can imagine by reading my name, I'm also Brazilian) :
Sorry, I don´t know about the division in English or French dialects.
In Brazil, the language has a lot of verbs and words that has different
meanings to the same in European Portuguese.
Also the correct writing is different in a lot of ways.
The interface of almost all the programs is translated to Brazilian
Portuguese to be more accepted in the country. "File" is "Ficheiro"
in the
portuguese translation and "Arquivo" in Brazilian translation.
"Display" is
"ecrã" in portuguese and "tela" or "monitor" in Brazil. The
"pt" is changed
to "pt-br" to eliminate the confusion.
You can say a whole phrase that has two different meanings in Portugal and
Brazil, using the same words.
That could lead to interpretation mistakes from time to time.
Also there will be confusion on the correct writing, since the articles are
not written in the correct way used in Brazil.
The language (with all the differences) is used by 180.000.000 people.
I don´t know if that is significant difference to the Wikipedia standards,
to justify a Brazilian Portuguese project. It is for a lot of other
projects.
Is it significant ?
The hardest problem concerning the portuguese wikipédia isn't in
differences between
the european and american portuguese. In general, the differences can
be well understood by both people, and, for the hardests differences,
the community must make efforts toward provinding rules for writing
articles that can be well understood for every portuguese speaker.
Note that these are no special rules; rules for writing good articles
must be provided in any wikipedia: consider the differences existing
even inside of the brazilian portuguese (we would need to conceive
such rules even if we had a separate wikipédia).
The main problem we must focus on is to increase the quality of the
portuguese wikipédia. For example, let's look at:
http://pt.wikipedia.org/wiki/Filosofia_do_direito
That is very easily accessible from the page [[pt:filosofia]], which
in turn has a link from the main page of the wikipédia. Even being a
stub, it looks like a regional article, citing Brazilian law's
philosophers (and not citing Portuguese ones). If it's really
important to cite such philosophers, one should create on that page a
section "Law's philosophy around the world" and cite them in an entry
"Brazil", so, another one could add an entry for "Portugal" or any
other country. Or one could even create a page "Law's Philosophy in
Brazil", if the subject is worthy.
Such bad written articles are harder to understand than those with one
or more meaning-misleading word, beyond making the reader to read
possibly-insignificant text, while the other possibility has, at
least, the advantage of making the reader to have contact with new
existing words.
Much work in increasing the quality of the portuguese wikipédia and
bringing new editors to it must be done before thinking in breaking it
in two or more. For now, we need to stay together, imho.
Regards,
Riba.