When will the 8051 and othe 8-bits go away?

This is a bit dumb, but let's discuss it anyway.

The 8051 and other 8-bit microcontrollers have had a long and
distinguished life so far. As more and more low power devices appear
using 32-bit instruction sets such as ARM, I wonder how long it will be
before 8-bits are no longer selected for new designs.

Some fun questions for a Friday:

1. For NEW DESIGNS ONLY, can you guess at how much life (years,
decades) is left in 8-bit devices?

2. Given microcontroller size/power evolution, do you think
ARM/AVR/other will end up in the smallest 8-pin(?) microcontrollers and
8-bit micros will just fade away? If so, in what time frame?

3. Do you think there is value (to embedded engineers) in settling on a
single ISA for microcontrollers, such as ARM?

I like ARM and I also like 8051, PIC and other 8-bits, but ARM is so
easy to work with (both in 'C' and assembly) that I wouldn't be sorry
if the 8-bits were retired.

What are your thoughts?