You can also look at this another way. This project could provide a financial incentive for individuals to develop more optimised GPU prime finding algorithms, the theory of which could lead to a greater understanding of prime number distribution e.g. a new sieve or similar construct.
Sunny, can you please clarify whether this project is finding new prime chain sequences within the known prime numbers or actually trying to determine new, unknown prime numbers using the prime chains as a proof of work.
Of course these primes are all 'new'. Finding 'new' primes is not the point, and primes are super-abundant there is no database can store them, it's always trivial to find one not stored in any database.
The point of GIMP is to find the largest known (Mersenne) prime, while the point of primecoin is to find longest chain of reasonable size limit (256 bits to 2000 bits as currently designed). Which one of the two projects is more useful is highly debatable actually. Mersenne has a very long history of study, its infinite existence is not known and they are scarce (only about 50 of them known). While for prime chains, as pointed out by my design paper, these prime chains are connected to the distribution of primes, their infinite existence and distribution is among the top wonders of arithmetic, you know how much mathematician value twin prime conjecture right? At right now I think some mathematicians consider the distribution of these longer chains hopelessly untouchable, and maybe will stay another millenium