- ILC -- Interchangeable Lens Camera, which describes everything from SLRs to Rangefinders to mirror-less cameras.
- MILC -- Obviously, an extension to ILC with Mirror-less out front.
- EVIL -- Electronic Viewfinder Interchangeable Lens is more precise but technically includes Sony's SLT line of translucent mirrored cameras, as well as mirror-less cameras.
- CSC -- Compact System Camera could mean just about anything, including point-and-shoot cameras with a large number of accessories and snap-on lenses.
- MSC -- Mirror-less System Camera to me, defines the category the best, but leaves the interchangeable lenses to the imagination. Obviously, it could include point-and-shoot cameras, but I believe it is closer to a narrow definition. Alternatively, MILSC and MSILC are getting a bit long, and I get to feeling like singing "M-O-U-S-E" after saying or spelling it.
- DSLM -- Digital Single Lens Mirrorless. Added by Panasonic with the arrrival of the GH3. It's very clear what it is, but then, they used it with the rangefinder style GX7, so it might not make as much sense.
In any case, I think it's going to be a while before the category has a definitive name or goal.
I'm still interested in how Olympus' E-M5 stacks up against Panasonic's DMC-GH2. I think it's apparent that Olympus has been doing quite well with still images, as Panasonic has been doing with moving images. The GH2 is in need of a few upgrades and a weatherproof body, and they're supposedly on the way, but haven't moved to manufacturing yet. By the time the GH3 is out, the E-M5 will probably be feeling old.
Of course, Panasonic's G3 and GX1 have been out a while, as have Olympus E-P3, E-PL3, and E-PM1. So, only the models numbered 5 are truly fresh, although the GX1 hasn't be around all that long.
I feel a bit sorry for Samsung and Sony. They keep throwing money at the situation, but they're not really making a lot of positive progress. Nikon are probably selling their 1 series pretty well, despite its shortcomings, simply because you can fit it into a purse easily. Why have a compact camera, if it's not really compact? Nikon put their money into the 4x6 print crowd. It's a bit too much to say but Pentax's tiny Q-system can barely manage a 4x6. It's not that small or that bad, but it is at a disadvantage and their K-01 is the odd man out being the size of a dSLR but allowing their large collection of lenses. You might as well carry their K-r compact dSLR.
Seeing as how Canon punted with their PowerShot G-series and Nikon brought out the D3200 with 24MP, you have to wonder if these mirror-less system cameras will continue to invade the top 10 lists around the world.
Update 2014.01.09: They've all made progress but the terms are used without much thought. Mirror-less cameras have come a long way and even Canon is on their second generation body finally. micro Four-Thirds (Panasonic, Olympus and now JK Imaging/Kodak) and FujiFilm seem to have the lead.