Apple has surprisingly just released IOS 4.3.5.
Apparently if fixes a certificate verification bug, however everyone should steer clear if you want to jailbreak.
4.3.5 will still JB tethered using redsn0w, but iPad2 users will have no joy with this firmware.
We are still waiting to hear if the baseband has been updated, rendering the iPad2 3G respite using TinyUmbrella useless.
In the meantime I have updated the downloads sticky with links - Official Apple IOS Firmware Download Links for iPad