I thought I'd share how I setup Thunderbird 2.0 to handle Gmail accounts so the folders match up. First follow the install instructions from the Gmail website for Thunderbird 2.0. Then, apply the following:
*) Go to Account Settings -> Server Settings
*) in the box that says Server Settings, click Advanced...
*) For the IMAP Server Directory, type [Gmail] (with the brackets)
*) click OK
*) Go Account Settings -> Copies & Folders
*) check Place a copy in:
*) select the Other: radio button
*) select the Sent Mail folder under your Gmail account in the dropdown
*) Repeat the above process for Drafts & Templates, choosing the Drafts folder on Gmail
*) Go to Account Settings -> Junk Settings
*) Repeat the above process for the Junk folder, choosing the Spam folder on Gmail
Thats it! You will no longer see a [Gmail] subfolder, and your Sent, Drafts, and Spam folders will match up to the correct Gmail folders.