Looking back on this thread, I've been playing Mark of the Ninja lately, and what strikes me is how it uses dynamic lighting. Finding examples is pretty easy, google images has plenty. The lighting itself is somewhat cone-based and has a 'textured' look, but it can be 'blocked' by solid objects, like the lighting from Construct Classic.
Remember how the light object and the shadow behaviour from Construct Classic worked? I've already stated how I think they could be greatly expanded upon in concept in Construct 2, but I also think Using polygon-based lighting instead of cell-based is a reasonable compromise. Since sprites in Construct 2 already use polygons for collisions, it would probably be far less computationally expensive and much easier to do than cell-based lighting.
I know I like to keep bringing up Starbound, but this is incredibly cool stuff:
<img src="http://www.abload.de/img/starsrourw.gif" border="0">
<img src="http://i.minus.com/dpYoU9h0gaF98/Starbound%20Day%20Cycle.gif" border="0">
<img src="http://i.minus.com/dtzx3VUL8rfnu/Starbound%20Lighting%201.gif" border="0">
<img src="http://i.minus.com/djWrYgW05S0kL/Starbound%20Lighting%202.gif" border="0">
And you don't really need cell-by-cell lighting to replicate the same results (aside from the way the light 'penetrates' into the ground, but still).
Now, the thing is with such lighting solutions, good luck trying to make them work with just events. I think it would be a good idea for an official or unofficial plugin to be developed for polygon-based lighting, with as many options as possible for what developers want with lighting in their games, whether it be pitch-black darkness in absence of light, or just low light for stuff like stealth-based games.
I'd also like stuff like specifying image points for the 'origin' of the light itself, like a light attached to a gun, for example (as shown in Mark of the Ninja), and also being able to adjust the angle of the light without changing the angle of the object itself (those last two suggestions I also want to see applied to the Line of Sight behaviour).
So, yeah. Polygon or grid-based, I don't mind as long as it works well, I just want a good lighting solution, dangit.