The rumored plane didn't show - but I stuck around to see what else went on during a weekday (since normally only get out to the airport on weekends or in the evening).
I was rewarded almost immediately when one of the Air National Guard KC-135's took off - right past my vantage point in the Terminal garage. [click any of the pictures below to see the image at full size].

Then I caught the daily Hawaiian Airlines flight to Honolulu (this is the 2nd largest passenger airplane that regularly operates in and out of Sky Harbor).

But the airplane I was the happiest to see flying - was the Honeywell 757 Engine Test bed. It took off and flew racetrack patterns for a couple of hours before returning to Phoenix.

I had gotten fleeting pictures of this plane before - but never its right hand side - where the extra test engine is mounted. The slideshow includes some of these older pictures - as well as pictures of the Boeing coming back into its parking place (directly off the runway).
Definitely a great way to spend a day taking pictures.