Not way to have any idea until at least the GM is out, any guess at this point will be 1000% speculation, would be like guessing how long the JB for 5.0 will be.
all we know is that current JBed devices would be able to at least be Tethered jailbroken, but the a new Exploit need to be find and work on in order to make it untethered. Comex and Dev team said they have "some" exploit that "may" work, however as i said until the GM is out there is no way to know (they may find and patch those before the GM)