[joezydeco]

Unfortunately with the way the phones are constructed today, the glass has become an entire assembly.

When you etch the touchscreen on the back of the glass and then bond the whole thing to the LCD with optically clear adhesive, you've created one single piece that's nearly half of the phone's guts.

If people are okay with the LCD moving backwards and leaving an airgap like the first phones, then perhaps it's possible.