Another approach might of course be to try to boost self-control. Self-control correlates with being able to delay gratification, long-term planning and career success. An enhancement of this would be socially and individually beneficial, probably far more than most other cognition enhancers.
There are experiments that demonstrate that glucose drinks can actually boost depleted self-control: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17279852 and presumably there might be more deep methods of enhancing it. So one strategy of handling the rise in temptations is to make us better at handling them.
An interesting and rather worrying paper is this, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=14756934 which argues that it is the flow experience of games that hooks us. Normally flow is hard to achieve through stimuli, which at most just generate happiness, but the more profound flow state seems triggerable by the right games. This goes beyond mere habit-formation to get a pleasurable stimuli since the highly motivated flow state involves using all mental resources to prolong and expand the state. So we might not just have to learn how to overcome simple pleasure temptations but also complex flow temptations.
Overall, enhancements of strategic individual thinking would be extremely useful. But there are no guarantees they will be developed at an equal pace as the games.
Richard Hollerith pointed out that the glucose drinks only last for about an hour, which is true. It is less certain that they are followed by a dip in self-control or that their effect is by affecting the neurotransmittors. Even if it is, it is a start for some serious neuropharmacological hacking. The serotonin system is already of interest in this respect: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=17360806&dopt=Abstract
A real willpower enhancement is likely something much more complex. Ideally we would like to strengthen our second order desires (at least some of them, some of the time). That might involve finding some pretty disperse neural nets, or more likely having a close symbiosis with software acting as an artificial superego. Design and implementation is left as an exercise :-)
It seems that one could trap this kind of desires too by games fulfilling them. If I have creative desires, spending a lot of time creating in Second Life would meet them. Maybe one could create “games” that help the third world in some way, trapping people with an altruist motivation (my favorite example is the spiders in the comic http://www.e-sheep.com/spiders/ ). The worrying thing is when the game shapes or constrains the activity into something less useful than it would otherwise have been. First order desire games trap us by providing simple stimulation, second order games by providing complex stimulation and meaning. But just as the stimulation in Tetris is fairly scripted the meaning and interaction in WoW is limited. Perhaps the healthiest aspect of the online games is how many players deliberately set out to expand their scope and circumvent their limitations. Maybe that is the solution of game addiction: try to ensure that the games are expandable and could in principle become arbitrarily complex. But that will still not help the people content with fulfilling first order desires.