Just asking if 2.0 uses the same lenguage files that 1.4
No they don't. Its in a new format
Example
$txt['113'] would turn into $txt['profile'] (Though thats no an example)
so there isnt translations (i need spanish) yet? if not, someone is working on them?
There is translations for some languages. But (regular) spanish doesn't seem to have yet.
You can check translation available from http://www.simplemachines.org/download/?languages
Someone can tell me what files have all the text lines so i can start translating?
The English language files will have everything.
i found a built-in idiom installer on the 2.0 searched for "spanish" and installed well :) no problems yet
The following site has all the $txt[] strings for SMF 2.0b3, you can use that to help in any additional translations.
http://huw.org.uk/smfstrings/