That's a good map, but it's also worth noting there are subdivisions as well. I was born and raised in the Northeast area of the State of São Paulo (SP), close to the border of Minas Gerais (MG), and there wouldn't be all but any differences from there to Londrina, Paraná (PR), where I live now; however, if you go just some kilometres south from here, the accent starts to change (and
ekalin, living in Curitiba, the capital city of Paraná, may confirm that), and in Southern Santa Catarina (SC) and Rio Grande do Sul (RS) it'll be very, very different. People in the city of São Paulo have a very unique accent as well. And someone from Goiás (GO) would also have a more peculiar one. But in that map those would all be included in the Southern (
sulista) dialect. I'm also told by a friend from Bahia (BA) that, even though we Southerners and Southeasterners can't usually realise that, it's easy for Northeasterners to tell whether someone is from Maranhão (MA) or Sergipe (SE), for instance, just by their accent—something
E}{pugnator might confirm or deny for us. Vocabulary may change as well—no one here in Londrina knows what a "talha" is, even though it's basic vocabulary in my hometown (the first time I said that here, people just stared at me as if I had taken, as my ex-girlfriend said, a word from the Bible! :shock: ). But don't worry, you'll certainly have no problems adapting—in the overall view of the language, such differences are really only details, as it certainly happen in most countries, especially the larger ones.
You might think of Brazilian and European Portuguese being as different as American and British English—though the difference might be just slightly larger, they're certainly far from being enough to make communication a problem. I guess Brazilians usually have a "harder" time to understand the Portuguese because the European Portuguese phonology is more complex than ours; that'd be the reason why Portuguese speakers usually understand Spanish easier than Spanish speakers understand Portuguese—even though it just takes some getting used to to overcome that, I believe.