The x86/x64 isn't going away anytime soon (sorry ARM), so it's not like all of my software will suddenly become obsolete overnight. Only a handful of my emulators use JITs (Desmume, Dolphin, PCSX2) and even then only Dolphin and PCSX2 require them for decent performance. Everything else is highly portable (usually C++/SDL).
Quantum computers, as far as I know, don't have advantages for all computing models, just some. That is to say, they probably won't be killing silicon. Even if it did, that's likely some decades away from now. However, 10 years is too soon to expect anything that life-changing for any of us in the emulation community. It's not like quantum computers won't run Linux anyway...
The only current issue of portability I see are getting emulators to run on phones and tablets, but even in 10 years, I honestly don't think we'll be living in a completely "Post-PC" kinda world. So in short, I don't think much will change except for how awesome the emulators get over time.
Quantum computers, as far as I know, don't have advantages for all computing models, just some. That is to say, they probably won't be killing silicon. Even if it did, that's likely some decades away from now. However, 10 years is too soon to expect anything that life-changing for any of us in the emulation community. It's not like quantum computers won't run Linux anyway...
The only current issue of portability I see are getting emulators to run on phones and tablets, but even in 10 years, I honestly don't think we'll be living in a completely "Post-PC" kinda world. So in short, I don't think much will change except for how awesome the emulators get over time.