Moore's law has failed in the digital camera development/marketing cycle. Time and time again. Digital camera technology available to the consumer (therefore at "consumer" prices) has just not advanced as a whole at a rate equivalent to (for example) desktop hard drive size/deployment, desktop/mobile processor speeds, etc.
There's a lot more to a digital camera than a mere sensor. And in fact the whole ball of wax, even though it's becoming somewhat of a commodity market in a number of respects, is much more than a sum of the whole (whole bill of materials anyway). A lot can be done to improve all-in-one as well as DSLR cameras with technology that exists today. I can argue that a lot more could have been done each and every year over the past 6 beyond what WAS done. But, for one reason or other, it wasn't. Perhaps it was a matter of market acceptance/timing. Who knows.
To make a rather open statement such as "at some point in the not so distant future we'll be using compact cameras that rival more complex and expensive systems currently in use today" is rather useless. That's a simple economic fact that has been proven time and time again in countless industries. Now if you can pin-point an exact date and conceive of a specific solution, then you may have a chance to make quite a bit of money. There's always some under-serving going on in all markets.
I think the most important point I want to make is that there wil always be room for bigger and better. That means when you think you've got the killer all-in-one, someone else will have the super-WMD bad-ass discrete that's even better. The best technology is always going to be the bleeding edge. It's always going to be the new development that companies have yet to recoup their investments on. Such technology is going to appear first in higher end gear first, regardless of where the bar is to mark that high-end point.
So you show me the $500 camera that's as good or better than today's US$8000 Canon SLR and I'll show you a $5000 camera that's an order of magnitude (or a couple) better than that. Just let's not get anyone expecting to see that in the next two years because if past camera development and marketing efforts are any example, it's just not going to happen.
Hey, power to technology. I want one of those future small cameras. Of course I also want the big sh*t-kicker I can use to clobber any would-be burglars.
Bruno