I'd rather have an AM2+ instead of 478 or even 775, IMO..
LGA is actually a better way. It allows for more contacts in the same space (LGA775 CPUs were about the same sizw as PGA478 CPUs) and allows for more surface contact. Plus chances of bending a pin in the socket are lower than on the CPU.
As for AMD, they have a LGA socket for servers already, LGA1944, and I have heard they plan to go with LGA on consumer boards in the near future.
To the OP, your original P4 2.4GHz is a 478, not 457. There is no 457. P4s started on PGA 423 then went to PGA478 and then LGA775 briefly.
Go with a newer LGA1156. You will need all new hardware but yours is way too outdated to upgrade.