I am having trouble rationalizing a GX1 + LVF2 purchase. Especially given the likelihood that Panasonic's new accessory port will be orphaned in a year or two.
You should never, ever assume that anything that's proprietary is going to be supported beyond the current generaton. About the only exceptions I'd make to that would be flashes and lenses. Batteries certainly aren't guaranteed to be the same on the next model, and EVFs even less so.
And yet Olympus managed to solve the very same issue two years ago. Got a VF2 for your E-P2 or E-PL1? Still works on current models. Got a VF3 (different resolution)? A firmware update and you're good to go with your old E-P2. (Perhaps not E-PL1, not sure.) And we don't know for sure, but it's reasonable to assume that if Olympus survives as a company, current accessories will work for at least another generation or two, even if new ones come along that aren't fully backward compatible.
So, sure, I get your argument, but it would be a whole lot more persuasive if we didn't have the example of Olympus staring us in the face.
Again, I'm not going to speculate on Panasonic's motives for designing a very limited accessory port the first time out. I have no idea exactly why they did it, but the most generous word I can use to describe what we see of their approach is "shortsighted".
Don't treat it any differently than if you were buying a G3 with an integrated viewfinder. If a GX-1 plus LVF-2 are worth the extra price to be able to choose when or when not to deal with the bulk of the viewfinder, then go for it. Otherwise, don't. If you base your buying decision on the idea that you'll be able to spread the cost of the EVF over multiple camera models you're asking for disappointment.
I have to disagree. I don't think it's at all unreasonable to expect an expensive accessory to be useful into the next generation of host devices. New accessories on old hardware? In that case I'm much more forgiving, though in this specific case Olympus makes Panasonic look terrible on that score too.
Of course, I am only
assuming that Panasonic's new port will be as short-lived as the last one. But I don't think that should be the default assumption at all -- Panasonic's recent behaviour pushes me to make it. I do not make that assumption when I buy a Firewire or USB peripheral, I didn't make it when I bought a Panasonic TV with an iPod dock, and I don't make it when I buy a memory card.
At some point, backward compatibility and future proofing will fail in all those cases... but two years is an absurdly short lifespan for this kind of system.