Folks keep asking the question. The answer is "Do not Make Purchasing Decisions Based on Rumors" A exception might be a CR III rumor with photos of the product. Rumors are not reliable in general, they are great for discussion, but don't take them too seriously.
Some have been waiting thru 7 years worth of rumors to get a 100-400mm MK II.
Thank you for the links. I did search briefly before posting but didn't find those.
As far as my questioning, everyone has good solid answers, both here and those other links. And, if it was purely based on rumors, I wouldn't have even posted. But when you look at the timetable of body releases, the rumors and what the market is doing, it seems like the 5DIV should be dropping very soon. But then again, I don't have the ability dig in and find out whats going on at the electronics shows, and what-not, like some of you may.
When I got the 6D last year, it was the same sort of deal that B&H has right now for the 5DIII. I still feel like I got a good deal, but after shooting with the 6D for a year, I really wish I had just invested in the extra grand and purchased the 5DIII instead. Then, right now, I'd be looking at $3-4K on some really nice glass instead of another body. I really don't want to be in this position again next year, but as my yearly budget for camera gear isn't bottomless, if they bump the sensor up to around 30mp, improve high ISO noise and increase FPS on the 5DIV, I know I'll be a big ole sucker and have to have it instead of lenses for another year. I know there's always going to be a better camera around the corner, but if it drops in 3 to 6 months after I purchase the 5DIII, I'm going to feel really burned.
@tphillips63, I know to many people that would be a good option, but I'm one of the unluckiest people around. Used or grey market, I'd get it and something would go wrong. Then I'd really be bummed.
If I can suggest something.
Make a plan. Decide what type of photos you take, what focal lengths you use, and what it is that is holding you back. Also decide the urgency of your gear needs.
I have a 5D MK III, and had the MK II, the MK 1, several 1 series, and many of the APS C. I've also had DSLRS from Nikon and Minolta. My Nikon D800 was fine, but the high MP slowed down processing a lot, particularly noise reduction, so its not a general purpose body, but more for studio or landscape with a tripod. All are just tools, and, while I like fine tools, I could do pretty well with any of them except when it comes to high ISO shooting.
I used my 5D MK 1 as a backup to my MK III last week, and actually found that I preferred the look and colors better than my 5D MK III. Unfortunately, ISO 3200 was not really enough, since I needed a higher shutter speed, so a lot of photos were blurred due to motion of the performer.
I'd be happy with a 6D, I don't go for using high FPS, but rather resort to timing, its really not that difficult. I've done 10 FPS, and I don't like wading thru hundreds of photos to find the one I would have taken with a 1 shot setting.
So, decide what you actually need to reach your goals, and then purchase the items 1 at a time, or as a group.
You can get a pretty good price on a 5D MK III thru Canon Price Watch ($2399). Its from a authorized dealer, with full warranty. It may be a better deal than the one from B&H.
As for prices, its a matter of global economics, and demand coming together to create a buyers market. The US dollar is strong, which means it will go further on imports. This plus slow sales overall continues to push prices down. This also means there is little incentive for Canon to introduce a $4,000 1D Mark IV and see few sales. They can cut prices on the MK III and make more money.
The one area where they need to act fast is in the mirrorless segment, they can easily see that they are missing out in getting a share of those sales. Expect a mirrorless camera to arrive soon, and it just may be FF. Also expect a new series of lenses for the mirrorless. That's one area that might be worth looking at before you buy.