Nikon has released the D600. It is a full frame 24MP camera with a slightly reduced AF spec (compared to the D800). The main difference is the lower pixel count compared to the D800's 36MP. The D800 retains a very useful DX mode and produces 15MP images using DX lenses. This a great feature, especially for stock photographers, as it lets you move up to full frame while keeping a relatively high pixel count using existing DX lenses. My vote would be for the D800 for the minimal dollar increment. The D600 sounds like it has a compelling video spec as well.
Today Canon announced the Canon 6D. A cheaper alternative to the 5D (similar price to the D600). Its key features are a 20MP sensor, wifi and GPS in a lighter, smaller and cheaper body. I'm not sold on who is uploading images right to social media from a dSLR without editing, but the wifi also allows for remote control which is a nice addition. Frankly, I don't see much for stock photographers over the 5D Mark II, which is now available at the same price. The 6D has a better AF system, to be sure, but most stock photos aren't shot in available light at high ISO. Even with my Olympus micro four thirds body I can't recall missing a shot due to low light, where I would have actually got a quality stock photo out of it. Wedding photographers will be delighted, I'm sure!
Canon has also announced the PowerShot G15 which sports a fast f/1.8 to f/2.8 lens. This gives it an automatic 2 stop advantage in low light compared to previous models. It doesn't have the bigger sensor of the G1X, but should be a much more capable camera that most compacts, and offers a bonus over the S100 (now S110) at the tele end. While this seems appealing as a small camera for stock, I think that the Sony P&S and mirrorless options are better bets for stock, or even the Canon G1X.
Panasonic has launched the GH3, a more rugged and bigger body than the GH2. Its key specs seem more video related, though it looks to be a better all around camera with a higher resolution EVF, new sensor, more dedicated buttons. In the end I think this will appeal a lot of video is your thing, but otherwise tough to justify this camera for still photography.
Olympus bring out two new viewfinder-less bodies to bring the OM-D sensor to the smaller bodies. Both great options, I would be very happy to take along a small body and pancake lens with the OMD sensor. The older 12MP sensor was hurting Olympus's image (literally) as it didn't really deliver the goods on having a larger sensor compared to the latest compacts. This should put the advantage back to MFT over P&S options.
Lenses: MFT has a number of new lenses annouced or previewed, including a 60mm Macro, 17mm f/1.8, 15mm f/8 (panfocus body cap!), 150mm f/2.8, 42.5mm f/1.2 and the Panasonic 35-100mm f/2.8 zoom is finally here. Good times. I won't belabor the point on why I think MFT is a great choice for amateur stock photographers, but the format is really getting flushed out with great bodies, sensors and lens options.
Sony is really attacking the photography world. With last year's excellent Nex-7 and their high dynamic range sensors in just about everyone's cameras, they have a solid foothold in Photography after only a few years of being the dSLR game. This year bring the SLT- A99, a 24MP full frame body with their translucent mirror technology. If you are looking for a new system, Sony is the only one that offers small mirrorless bodies with an APS-C sensor, mid range SLT bodies and now full frame using an excellent EVF in all options. Further, Sony seems to be taking it seriously and making sure the AF on phase detect lenses has a very good solution with their adapter that includes a mirror module. Not having an established following, Sony doesn't have to worry about taking sales from SLRs when making a mirrorless. My eye is on Sony, as they really seem to be innovative right now. Especially since they finally got rid of the non-standard hot shoe! Focus peaking seems to be included across the line, and is a great feature not possible with an optical viewfinder.
As well, Sony has also got a new fixed lens compact with a full frame sensor - the RX1. This seems like a bit of a concept car with its $2800 price tag. I've love to win one, but pretty tough to justify a fixed lens compact for stock photography.
Fuji has released a smaller body (the XE1) for its mirrorless lineup, and continues to build the lens line with some zooms and more fast primes. I love the idea of the Fuji mirrorless, but a bit pricey unless it is your only camera. I'm not sold on the studio side of the Fuji in terms of flash options, nor its odd sensor which requires a different de-mosaicing algorithm. Sometimes you want a camera that has a lot of people using it that you can go to for support...
Have fun checking out the new tech!