Looks like i0n1c's untether exploit has also been patched, so 4.3.4 will be a thethered jailbreak for devices susceptible to limera1n (inc. iPad1) unless a new untether exploit can be discovered...
And it seems confirmed that iPad2 3G GSM & CDMA owners are indeed out of luck as suspected if they update to 4.3.4 by accident. Blobs will not work to downgrade.
You have been warned folks! ;)

