O dear, you read the Offsets.h file from Pocketgnome... Did you read the version?
Code:
// 3.2.0 valid
#define PLAYER_NAMES_LL_PTR ((IS_X86) ? 0x151C2C4 : 0x0) // 3.2.0
Current wow version: 3.2.2, so, clearly, this will not work 
Also, PG doesn't hard-code the offsets anymore, it uses a byte signature scan. Fire up pocket gnome when wow is running and it will print the latest offsets to /private/var/log/system.log. There you will find the latest.
And check out scanObjectGraph in Controller.m if you want to see how to parse the object list (which you're referring to as a player list)
Also, search the forums for info on object lists, there is a shit ton of info