This is getting silly now.
Games in all genre's keep the same engine afew times in most cases ,when new releases come out.
Just ripping up the core game engine every time doesnt happen. If you look at the GTA games the core engine was pretty much the same over the course of the various releases.
Some games can do good with reusing the same engine. Look at the Source engine that Valve used with Half Life 2 back in 2004/05 which is still in use today although a bit updated and as of now they are working on a new version of the Source engine which is still the same engine just upgraded more with new features added. To be honest its hard to let a engine like that just die out when it is so good on resources and giving you high quality graphics that even a avg computer can run without lag.
I actually saw an improvement in graphics, I'm looking past the fact its not worth the full price.
Personally I dont think many games today are worth the price they charge. Then again I grew up with pc games that cost $40 when new and 3 months after release they would drop down to $19.99 since the business already made their money back on the item. Now a days you can still see a $40 price on a game 2 years after it came out. For instance Fallout 3 is still $49.99 here even though we have this New Vegas game coming out at the same $49.99 price. I personally think $50 is kind of steep for a game that always has the possibility of not working nor not being to your liking since theres no demo to really try it out on your rig and see what you think.
That was the only way I justified the $50 for Mafia II was I put a good 5 hours worth of screwing around in the Mafia II demo that only gave you 10 mins of driving to get to the mission.
But I did love Fallout 3 and I know Ill love Fallout New Vegas either way. Cant wait to see all the lighting in game and see how they went about doing it, wonder if its like the DC light mod I downloaded for FO3.