The iPhone SDK has been delayed according to engadget and ars technica. Today Apple sent out invitations for an "iPhone Software Roadmap" event on March 6th.
The iPhone SDK was originally scheduled for February. It appears a new iPhone SDK release date will be announced on March 6th, since the invitation specifies a 'roadmap'. Software roadmaps are a description of future features and expected release dates.
Further announcements about the aPhoneTracker release date are delayed until after the March 6th news from Apple.
To get aPhoneTracker software, register here.