Considering that Spinel is a magnesium aluminum mineral with the symbol MgAl2O4, this could be the code name for an aluminum clad Windows Phone handset. The other names lend themselves to a number of various interpretations.
Windows Phone has picked up momentum in 2013, starting with the low-light photography niche, picking up speed with the strong sales of the entry-level Nokia Lumia 520/521, and continuing with the Nokia Lumia 1520 phablet with specs that rival that on any Android device. The latest data shows that Windows Phone captured 4% of the U.S. smartphone market in the third quarter. Perhaps one of the phones mentioned in the tweet will be the next big Windows Phone model.
source: @evleaks via WMPoweruser