This is what I am leaning toward for the moment.
I will keep the D90. I use it around the house where its size (compared to m4/3 does not matter too much). My brother is a Nikon shooter, so if push comes to shove, I have access to his Nikon lenses. For my purposes, I think I will buy Sigma 18-35 F/1.8 to use with this camera.
I will keep the 300mm F/4.5. It is an old manual lens and I will use it as a target projector to build a small camera tester in my garage (I used to build these things for a living and I have a project in mind).
The Samsung gear is going to go. I am not particularly concerned about Samsung abandoning the NX system, but I found that while NX500 takes very good images, for some reason it takes a lot more work in Lightroom to make them look good. I am not sure why, but it is easier for me to work with Panasonic and Olympus files. Another interesting thing I found is that in actual use, the performance of the GX-1 with the different prime lenses (I forgot to add the Olympus 17mm f/1.8 to the list above) is snappier that that of the NX500 with either of the two lenses I have. Also, looking at the NX lens line-up, the higher quality lenses are quite large, so I am in no danger of switching over to NX completely.
All my old 4/3 DSLR lenses will go. I probably can not get too much for them, but I think it is time to say good bye. I played with different lenses quite a bit over the last few days and to my considerbaly surprise discovered that the 12-40mm F/2.8 is actually a respectable macro lens. Not as good as a dedicated macro, but good enough for my purposes, so the 50mm F/2 is going onto the chopping block. The 50-200mm along with EC-20 has a bit too much overlap with the much more compact 40-150mm. I would have kept it, but since the 300mm F/4 is coming out, I need to start saving for it. The 30mm Sigma is a nice lens and I have used it for a number of years as a portrait lens (it is a little short for it, but it worked). I went into Lightroom and looked at what F-numbers I have been using it most of the time and it turns out I did not use it wide open nearly as much as I thought. With that in mind, I think I will switch to the 45mm F/1.8 as a portrait lens. It is a different perspective, but I played with it a bit and like it.
The 40-150mm F/4-5.6 will go too. It is a surprisingly sharp little lens, but the 45-150mm Lumix seems to have similar sharpness. Since the Lumix lens is stabilized I can easily use it with both of my m4/3 cameras.
25mm F/1.7 Lumix is new to me, so I am still trying to figure out whether I want to keep it. Initial image quality looks decent if I stop it down a bit. However, it is not nearly as compact as I thought (not sure why I thought that it would be that compact).
So far it looks like I've got enough lenses to have two m4/3 camera kits in two separate bags that would be suitable for different occasions.
Kit 1 will be GX-1 with 14mm F/2.5 (usually sitting on the camera since the combination is virtually pocketable for me), mZuiko 45mm f/1.8 and Lumix 45-150mm. Maybe, I'll keep the 17mm F/1.8 there as well, although I prefer to have it at work in my office.
Kit 2 will be E-M1 with 12-40mm F/2.8, 40-150m F/2.8 and FL-36R flash. The video quality with the E-M1 is surprisingly decent, so I think I will need to buy a microphone for it.
The Ef to m43 speedbooster will go, but I think I will buy a Nikon to M43 speedbooster. Together with the Sigma 18-35, it will make for a 12-24 F/1.2 manual lens. That will be pretty interesting to play with.