GameDailyBiz has a piece analyzing the value of the Grand Theft Auto Franchise
for developer Rockstar and publisher Take-Two Entertainment. At something like $900 Million over the next five years, the franchise is almost 80% of Take-Two's market value. From the article: " ... While it's hard to blame Take-Two for its reliance on a blockbuster franchise, eventually gamers are likely to tire of the GTA formula, or the games will no longer feel fresh when placed side-by-side with titles that perhaps improve on that formula. To be fair, Take-Two has made attempts to diversify itself through acquisitions and new IP, but the publisher's value right now is heavily dependent upon GTA and that could be a double-edged sword for potential suitors, or investors in general. "