It really depends. http://www.1up.com/do/newsStory?cId=3156044 Great story on Gears of War's costs (a $10m game) 25% (aka $15) goes to pay the art and design guys. 20% ($12) goes to pay the programmers and the engineers. 20% (also $12) goes to your friendly neighborhood retailer. EB / GameStop, whoever. 11.5% ($7) goes to a "Console Owner Fee" - ie. whichever one of the Big Boys made your hardware (Sony, MS, Nintendo.) 7% ($4) goes to marketing, and puts Mad World and Marcus Fenix on MTV. 5% ($3) goes to "market development" -- paying for cardboard Standees of the Gears Crew and elbowing other games out of the way for shelf space at your local retailer. 5% ($3) goes to actually manufacturing and packaging the disc. 5% ($3) is spent paying the Man for IP licenses or maybe hiring some big name voice actors. If your game isn't an original IP, here's where you get dinged by Marvel, Disney, or Ray Liotta's agent. 1.5% (just $1) goes into the publisher's pocket. 1.5% (also $1) goes into the distributor's pocket. 0.3% (about 20 cents) goes into corporate costs. Management, overhead, lawyers, etc. 0.05% (less than 3 cents) go into the cost of paying for the Developer's Hardware. Who knew an SDKs can cost tens of thousands of dollars? It also depends on the cost of the game. I believe the price of the game can effect the % to MS and such. XBLA is a totally different scale. MS takes around 30% of each download for server space, provided you give them a 100% working game. For 50%, MS will take your old game, and re-code it for multi-player and work on XBLA.
Back from the dead, I'm afraid.