Yeah, I have seen a lot of 570s come with inadequate voltage from the factory. You don't have to go crazy and raise it to 1.1v though. Try 1.025v and see it it solves the artifacting. If you need 1.1v to be stable at stock clocks, I would defintely RMA.
Don't RMA. There have been a lot of instances of manufacturers undervolting GTX 570s from the factory. Why would you go through the hassle of RMA, when the problem can be fixed with a slight bump in voltage?Besides, its not like 1.0v is high voltage. Some GTX 570s come as high as 1.025v stock VID.
Get the 580 and enjoy it! If you are always waiting on the next big thing, you will always be waiting, and never have any fun.
Besides, Kepler cards are still quite a long time away. Spring of 2012 is the earliest they will come, mark my words.