User blog comment:Spawny0908/This new DLC..../@comment-3455248-20110730172919

For comparison, I took a quick look at release dates for three modern console games I've played that had significant single player expansions. If I did my math right, the time between release of the game and release of the *final* single player expansion (not counting platform disparity) was 9 months for Fallout 3, 10 months for Dragon Age: Origins, and 18 months for GTA IV. It seems like most publishers fall into the "under a year" range, particularly for the franchises where a new full game comes out every year or two.

So, Rockstar is certainly willing to spread things out over a longer period of time than others. RDR is reaching the 18 month mark in November, however.