First, BL 4.6 + BB 04.02.13_G is done by the young well-known iphone-unlocking genius George Hotz(a.k.a GeoHot). Here’s his announcement on his blog. What does this means? Well, it means anyone who plans to use iphone on any unofficial carrier network can go to get an iphone without any hesitation for now. For OTB or upgraded 1.1.2 or 1.1.3, try Ziphone . For others, use google.
Second, one of FF 1.1.3’s exploits founded by Dev Team. So what does this mean, again? It means 1.1.3 has been jailbroken. It means you can try the newly-added features in the latest firmware yourself. Without this, you will never ever get Ziphone.
Basically, it means you can make your 1.1.3 OTB iphone fully functional(hopefully) while staying at the up-to-date 04.03 BB.
Besides, if GeoHot continues his awesome job, a customized BL would be possible. That means, most likely, the hacking community will take a big step advance in the cat-and-mouse battle against Apple. For the iphone owners like me, we will benefit so much from that. Say no worry of no available unlock method at all when we do the upgrade in iTunes