avr 8 bit vs 32 bit instruction set
Pretty much no, they are not the same.

From the AVR32 instruction set documentation (emphasis mine):


  To truly exploit the power of a 32-bit architecture, the new AVR32 architecture is not binary compatible
  with earlier AVR architectures.


In other words, code for the AVRs will not work on AVR32 processors, the instruction set is different.

While some of the mnemonics for instructions (e.g. ADD, ADC, etc.) look similar, but the instructions have different parameters, different registers, and differing behaviour.

However if you are using GCC or some other compiler, then as long as it supports the device, you shouldn't notice a difference if you program in C. If you are working in assembler, the instruction set will probably feel familiar, but it isn't the same.