A passage is blocked by 10' of ice (non-magical; it's winter, dungeon air is below freezing, so ice doesn't melt). The official solution is to cause x points of damage. In-bounds-thinking: hack with weapons/powers for x minutes until ice is all broken and cleared away. Out-of-bounds-thinking: maybe blunt weapons and axes will break the ice faster than swords and arrows (even if the rules don't differentiate between weapon type vs ice) or blasts of magical fire to clear the ice most quickly (even if the spell targets creatures and not objects* and/or doesn't do double damage to ice and/or you don't even reference the rules 'icewall, meet fireball') or there is NO obvious reason why we must blast through this icewall right now, it's boring hard labor (from a character POV) and we can check it out later.
Is that a good example, perhaps?
A good example of what?
The 4e DMG, p 66, says the following, under the heading "Object Immunities and Vulnerabilities":
Some unusual materials might be particularly resistant to some or all kinds of damage. In addition, you might rule that some kinds of damage are particularly effective against certain objects and grant the object vulnerability to that damage type. For example, a gauzy curtain or a pile of dry papers might have vulnerability 5 to fire because any spark is likely to destroy it.
So the idea that fire might be particularly useful against ice is pretty much part of the rules of the game. I think most players and most GMs would also assume that hammers and axes are more useful than swords, spears or daggers at breaking through walls or doors.
As far as I can see, there is not much more to "out of bounds" thinking than taking the fiction of the gameworld seriously. And, as the quote from the DMG shows, this is already part of 4e (and other RPGs too).
In my view the real issue, as someone noted upthread, is giving guidance on how to adjudicate these sorts of issues - like the suggestion that paper is vulnerable 5 fire (which implies, for example, that ice probably should not be vulnerable 15, at least against low-level attacks).
Player skills must always be of prime importance; otherwise, what's the point of you playing the game?
The big question is: what kind of skills do you want to use?
A good question.
A related question is this - what parts of the fictional world do you want to make salient via your "out of bounds" thinking? White Plume Mountain - which is what I was reminded of by Monte Cook's column - emphasises players paying attention to the fictional architecture and physical design. Personally I find that can get a bit tedious if overemphasised. I tend to prefer situations that encourage the players to pay attention to fictional relationships, loyalties, histories, personalities etc. "Out of bounds" solutions then become things like negotiating truces or alliances, playing NPCs against one another, analysing situations by reference to the imagined past of the gameworld, etc.
Whether or not the PC's abilities are used to bring those story elements into play, and/or to deploy them, I think is going to depend a lot on the details of the situation at hand, and the action resolution mechanics. Sometimes "saying yes" or free roleplaying makes sense. Sometimes a skill challenge is called for. But I think the issue of "fortune" vs "drama" vs whatever for action resolution is orthogonal to the issue of "out of bounds" thinking.