Microchip have only ever discontinued a handful of devices over the years as far as I am aware?
Of course at present, everybody and their dog are doing ARM, so a different processor core (MIPS) is sometimes a refreshing change, but if Microchip took over Atmel their product line would grow stronger, so I don't think they would discontinue the ARM line, as it just doesn't make sense, they are more feature rich than their PIC32 offering, and can run Linux on some of the higher end Atmel ARM processors.
Microchip AVR...Has a ring to it
I've never understood the "fanboy" arguments, if you use a particular part whether it is because you were introduced to it by someone/something and continued using it, then you will naturally stick to it, you won't be able to jump to another chip as easily as sticking with the "devil you know", I use both, and I use whichever better suits my application and what other engineers are used to, makes it easier for them to do some debugging rather than all on me!