Of Molnar's pull requests, the x86/boot changes caught my attention. He mentions "more boot time optimizations."
The noteworthy work there is Len Brown of Intel continuing to work on optimizing the boot speed for Linux x86 systems. There's four patches for the 4.3 merge window affecting x86/smpboot for boot-time optimizations, the patches can be seen here.
The work includes removing a 100 microsecond delay, removing up to another 500 microsecond delay in another patch, removing another 100 microsecond delay, and eliminating some dead code.
Len Brown has also been working on analyzing the Linux system suspend/resume speed.