Nope I don't think so. These engines will prove viable through the years to come and can be used over and over for sequels or entirely new IPs.
I rather see 6 different engines bringing something new to the table than 6 games using the Unreal 3 engine. Although Epic was very smart to do this.

FootballFan - "GT has never been bigger than Halo. Now do a comparison between the two attach ratios and watch GT get stomped by Halo. Reach will sell 5 million more than GT5. Quote me on it."







