I don't think it's (Vzw GS4) out yet, but given that we have one on Sprint - I'd say it won't be a far jump.
I honestly thought about helping get a device tree started but don't want to do it blindly. Also fair to expect a locked bootloader that will need addressed first - but I have heard this too is just waiting for GS4 release.
There's a 100% chance of having a good build. The only issue is whether at some point down the line new devices on VZ will be harder/impossible to bootloader-unlock so you can flash the build in the first place.