Not all of your default views in the Gmail web interface will appear in your IMAP client at this time. We're working on making Gmail for IMAP as much like the web interface as we can, but in the meantime, you won't see views such as Chats in your client. (Note: while you can add additional labels to hidden views to show up in your mail client, this may result in distorted messages or other unforeseen consequences.)
Most users should see all of the labels in their web interface replicated as folders in their IMAP client. If you're using an English version of Outlook 2002, Outlook 2003, or Outlook Express, but your web interface is set to a language that uses non-Latin characters, your folder names will not display properly. In addition, some subject and sender names may show as garbled text. This is an issue with these versions of Microsoft Outlook. For more details, please contact Microsoft's customer service department.