I'm with couchmonkey on this--both of these announcements are very good for Sony.
Honestly, it probably doesn't affect Nintendo that much because they're using a different strategy. However, if I were going to buy a non-Nintendo console, at these prices, I would totally pick the PS3 over the Xbox 360. Microsoft should seriously consider a price drop in November.
Caliban - the price will almost certainly drop for the US core pack, too. Otherwise, it'll be cheaper to import (even taking into account shipping).
The real question becomes if the $600 version is also going to drop in price. Last I checked, Sony was planning on shipping out 80% fancy and 20% non-fancy consoles. A price drop doesn't do much good if you can't buy the non-fancy version.