Users of the new Bungie.net site might find one thing to be problematic- linking their Xbox Live GamerTag. Although Bungie.net allows you to choose whether or not to display your GamerTag if it is linked, you can't actually link it there if it isn't already. To do that, you have to sign in to Xbox.com using the same Passport you use for Bungie.net.

If you haven't logged into Xbox.com lately, you may find some changes there, too-- users are being prompted with a message that they need to "migrate to the new version of our website", and if they log in with the same Passport account they used earlier, that they can keep their previous account settings. However, this doesn't appear to be working for everyone. At least one user (okay, me) has received an error message that only states "There was an error attempting to migrate your account." which isn't very helpful or informative. However, keep in mind, that was from Xbox.com, not Bungie.net.

SketchFactor has posted about this issue in this forum thread.