The primary resources (barring conferences) for research around game development that I've found is the Game Programming Gems books, GPU Gems and the AI Game Programming Wisdom books (Both can be found here).
Both series' feature articles from game developers as well as researchers and at the end of each article they offer a comprehensive reference list to further your understanding on the topic.
EDIT: Although the AI series has ended, they do have some great articles in there, well worth a look.
I would say that the main research efforts are focused on either graphics or AI, probably because they're pretty large areas of interest for academia in general.
The GDC Vault (found on the sidebar of this site sometimes) is also very useful as is GDC itself. Conferences are probably the way to go to keep on the cutting edge of research topics as well as networking to find out what some people are working on, etc.
A great conference for graphics is SIGGRAPH.
Good ones for AI: AIIDE and T-CIAIG.
If you don't have access to the conferences, you could always purchase the proceedings that have all presented papers and articles of interest within them.
A fairly old resource for finding game development research topics is Red3D. It's fairly outdated and a lot of links are broken, but with some Googling of the research areas you should be able to find them again pretty quickly.
Although not official (from an academic perspective), GameDev.net has a good few interesting articles on latest advances as does GamaSutra.
Alex J. Champandard runs AIGameDev and they have a lot of guest speakers, research students, articles, papers, etc. It's pretty comprehensive, but to really get the most out of it you need to be a Premium member which can be a bit pricy.
Hope that helps.