The hottest research topic in CPUs should be finding a better solder, one that doesn't stress / crack the die.
It's not just CPU's affected by this problem (BTW its the solder that forms cracks not the die)
Since the European union banned the use of lead based solder in 2006 a lot of research has been going on.
The problem of solder forming cracks/voids is a big problem for the whole industry, along with how to remove high heat loads from ever shrinking devices.
Everything is being looked at to solve the problem including Carbon nanotubes, Gallium based solder, and making the join in a vacuum just to name just a few.
Personally i think Intel using standard goop between the die and the IHS is a stop gap measure until something better is developed.