Given that CCP has now demonstrated that they have the coding capability to create zones of non-scanability, how about creating stuff like static nebula's and gas clouds that negate the ability to scan in OR out. Where there is a perpetual warp disruption field in place.

Large areas, thousands of km across, where fleets can hide, or even get lost in.
Put items/sites of value in in them though, where people REALLY have to explore, where you operate by your wits, overview and luck.

Some place that while it is easy to hide in, be it someone with evil or benign intentions, but also makes it very difficult to hunt someone down in the cloud.

I always imagined some kind of area like we saw in the Wrath of Khan, would be a very interesting to spend a few hours, or longer, in.

Edit: Expanded thoughts:

I don't really want to dive into specifics with this initial post, that is covered on page 3 of this thread.
I want to discuss general theme.

In my opinion, a whole lot of older players are looking for the "next horizon" within Eve.
They have done pretty much all that Eve has to offer, at least on a superficial level.
They are waiting for something new, hence the excitement about CCP opening up new territory with player jump gates.

But what if they can have that new experience within the confines of existing star systems?
What if they could experience a different type of Eve, where the game is played a little differently, where things are more claustrophobic, where things are a little more random, the risks higher, and the rewards also higher, where tried and true methods of PvE and PvP operation have to be altered, or thrown out the window?

On a different tack, Eve players are notorious for being way too smart for their own good. We quickly industrialize every PvE concept, or even PvP mechanism that CCP hands us. Does not matter if it is high sec incursions, or wormhole C6 combat sites, or FW plexes, or null sec sov moon goo.
The players will take a mechanism and will test and optimize the risk/return ratio.

But what if they faced a section of space where the rules are changed? Where things are so random, or so varied in possibilities that no group could optimize for any particular circumstance. Where industrialization of sites was impossible, where bad people could be anywhere? Where exploration and finding riches or prey was significantly more difficult than today, and the rewards matched?

This is the type of zone that I would like to see CCP create, and by removing some of the existing game mechanics as described later, where you are partially blinded, you don't know what you are facing. PvE sites and PvP situations can be so much closer together, since you can't see them, until you are virtually on top of them. Whole new meta's on how to play will be created.

The happiest time I had in Eve was when Apochrypha came out. My old crew, within Eve UNI, has our 1st POS up in wh space 5 hours after Apochrypha was released. We stayed for over a year, constantly upgrading our home, from a C3 to a C4 to a C5 with a C6 static. The sense of the unknown, the learning of new game mechanics, the heightened risk of no local, all made for a great experience.

I think something like what I am proposing could bring back that wonder and excitement level, and it would be oh so easy for all to access, as these zones could spawn anywhere. And if done properly, and if CCP jams enough variation of sites and potential combat situations into a zone, then it would be very difficult to optimize for anything. I am not talking about quantity of sites being in a zone. I am talking about variation of POTENTIAL sites. If one does not know what they will find any given day, the game becomes very interesting.