Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)
I've been untethered for around 2 weeks. Very stable as well. Not sure why it's beta.
It will ship with either 4.2.5 or 4.2.6. If Apple has already discovered the exploit (which they did, it's already patched in 4.3b) then it's safe to say it's patched in these verizon versions too.