This Dev Team has released redsn0w 0.9.15 beta 3, the third beta version of the program with which we can jailbreak our iDevices. In this update, the Dev Team has solved the problem that generates the appearance error 2601 when using a custom ipsw, with preserved baseband, in Windows, but also the error 14 that appeared after the stitching process. In this situation, the Dev Team recommends using the simple restore process of redsn0w and not the stitching method.
Update #2 (Nov 1): Version 0.9.15b3 fixes the redsn0w "error 2601" that Windows users were seeing using the Restore button. It also fixes a related Windows iTunes error 14 for stitched files. Note that if you have a baseband, you should probably avoid stitching and simply use redsn0w's native Restore (not iTunes).
Those lucky recipients of new iPad minis and iPad4s on Friday can use this redsn0w to save your 6.0 blobs off to Cydia. First connect your new device and turn it on, then use redsn0w's Extras->SHSH Blobs->New and point it at the 6.0 IPSW. Expect an ultrasn0w compatibility update for iOS 6.0 by Friday (mostly useful for 3GS old-bootrom users who are currently enjoying the untethered 6.0 jailbreak!). Same baseband support as with 5.x.
If iPad Mini si iPad 4, Dev Team recommends users to connect their tablets to redsn0w, to go to the menu Extract->SHSH Blobs->New, to choose the ipsw iOS 6 and to save the related Blobs in the computer and in Cydia. At the end, there is a mention about ultrasn0w which will be compatible with iOS 6, but it will also decode the old basebands, so don't have any illusions that you can decode something new. redsn0w 0.9.15 beta 3 can be downloaded available here.
