The numbering jump from 1 to (gasp) 7 indicates that Panasonic considers the Lumix GX7 more than a normal evolutionary upgrade. And they might be right, it certainly looks like a serious camera. I would call this a semi-pro camera at least.
Most importantly, for the first time for a M4/3 camera from Panasonic, it has in-body stabilization (IBIS)! Hallelujah! The lack of that (meaning prime lenses don't get stabilization) has been, in my eyes and many others, the main Achilles Heal for the Panasonics, which otherwise are excellent. But now you can use for example Olympus' wonderful 45mm or 70mm lenses, and have stabilization on a Panasonic body.
It's a bit bigger than the GX1, but with the added IBIS and now a tilting screen and a tilting viewfinder (a first!), I think that's justified, and while it may make it a not-pocket-camera, it makes for better handling when shooting for realsies. This is a real camera, not just a holiday camera.
I think it looks really nice too, maybe their best looking M4/3 ever.
I started with Panasonic when the M4/3 type cameras came out, because the Olympuses had slow autofocus. When Olympus got that fixed (and good!) I moved to them because they have in-body stabilization. And now both brands are up to snuff in all important areas, it's a tough choice!
But then you can mix and match like I said, for example use Panasonic, but take advantage of some of Olympus' top-notch prime lenses. Or use Olympus and take advantage of some of Panasonic's great zoom lenses, like their newly upgraded compact 14-140mm. It's all good.