I would be mildly shocked if it was, because (a) the relevant bits of QEMU are under GPL or LGPL, and it doesn't seem very likely that you could get $1.3m investment for a product you'd have to GPL, and (b) if you're interested purely in userspace application translation (and especially if you are happy to restrict to a single guest and single host architecture) then you can almost certainly come up with a better-suited design for that than QEMU (which is rather generalised and focused more on system emulation than userspace).

It does, assuming your ARM host is at least ARMv6 or v7 (v5 doesn't deal with unaligned accesses and QEMU userspace mode doesn't do anything special with guest binary unaligned accesses, so they appear as host unaligned accesses).

QEMU's i386 userspace mode emulation is a bigger problem -- most notably it doesn't handle multithreaded guest binaries (to an even bigger extent than QEMU's general issues with multithreaded guest binaries).

None of these are insurmountable problems; it's just that nobody so far has cared enough about them to put in the time to develop fixes and get them through code review on the mailing list. Patches welcome :-)

QEMU is regularly being used in the Emulator scene as a host for x86 binaries, mostly DOS stuff, though. Its a decent enough 8086 emulator, 386'ish too ..