From the Vlingo website:
Vlingo automatically capitalizes the first word of each sentence, and proper nouns that it knows about. If you find specific instances where it's not capitalizing something that it should, let us know and we'll forward it on to the engineering team. As improvements are made, you'll see the benefit automatically, without having to download a new version of Vlingo.
Note that Vlingo only capitalizes in messaging fields that are intended to be sent to other people, for example text messaging and email. It doesn't capitalize contact name fields, Note2Self, etc.
Vlingo does support speaking common punctuation characters such as the following: . ? ! , ; : * - + = Just say 'question mark', 'period', and so on.
Vlingo does not yet support speaking new line (carriage return) characters or creating new paragraphs. For now, you'll need to insert those manually via your keyboard.