They are investing money to continue improving their technology in their labs, but they all missed the cheap easy way to do so, by just decreasing the pixels.
I didn't mean that they have to decrease the pixels (sorry for my bad english), but I say that more megapixel won't make a camera much better.
I'm waiting for the 5D MKIII (or maybe the 7D MKII) and the least I want to see is an advertisment like we had the last years... "Yeahhh buy the new 5D!!! Now even MORE Megapixel and even MORE frames per second").
I don't say, that more sensor resulotion is bad. I want to see some REAL improvement. GPS, WLan, Touchscreen, more Video-functionality etc. Not just onother sensor upgrade.
The 5D II has almost 22MP. We've reached a very high level on sensor resulution - high enough. Who cares if the 5D III will have 22, 24 or maybe 30 MP?
And if a manufacturer "dares" to go down in the resolution I thought it was worth mentioning. Better resolution is does not necessarily mean better image quality.
And no, it is not a problem of engineering, it's a problem of marketing.