Great summary, Genew....

To extend the facts, I think Tesla will not walk away from the cyclindrical cell shape, but J.B. Straubel already announced, that Tesla will change the design in the near future. Probably for production in 2016/2017,may be earlier. The 18650 cell is not at an optimal size for electric storage in relationship to cathode/ anode ratios. Thus they will make it a bit more cylindical ( what ever that means).

Source: http://youtu.be/zWSox7mLbyE

I personally see Tesla and Panasonic developing a new gen of Li batteries, hopefully on the basis of EPFs technology. In my opinionen the statement from Musk "non-toxic production process in the GIGA factory" implies this.

Source: Tesla conference call regarding Giga Fab

Third, I would imagine, that the new cell shape "accidentially" has the same diameter and shape as the Maxwell Ultra Caps (which currently have a bit wider shape) to alow Tesla to combine both types within one battery pack module. MXWL just announced a more vibration and shock proof version of their K2 cells (imporantat for automotive application) and is on its way to get the tech ready for mass application.

Source: see MXWL webpage

So lets see if my puzzle parts fit together in the end, I am betting on it....

Cheers!