Now as to why this is important? Geohot’s Limera1n uses a userland exploit from Comex to make an untethered jailbreak for all iOS 4.1 devices. While Apple cant patch the original hardware based Limera1n exploit, the userland exploit though has been patched in the final version of iOS 4.2 firmware.
The next update to Limera1n based iOS 4.2 jailbreak tool will require SHSH blobs for iOS 4.1 for an untethered jailbreak on iOS 4.2. So if you don’t save your SHSH blobs now, you will get tethered jailbreak on iOS 4.2, NOT untethered.
Since Apple hasn’t released iOS 4.2 to public yet, now is the time to save your SHSH blobs to make sure you get an untethered jailbreak once iOS 4.2 is out. Once the public version of iOS 4.2 is released, Apple will stop signing the old firmware, making it impossible for you to save blobs for iOS 4.1. You can follow our step by step guide posted here to save SHSH blobs on iOS 4.1 before it is too late.