Verizon prolongs its free hotspot party on 4G LTE phones, but then what?

If you've been maxing out on Verizon's mobile hotspot offer that came with your new Samsung Droid Charge, HTC Thunderbolt or LG Revolution, then do carry on. The offer has been extended again, letting you use your 4G LTE handset as a WiFi hotspot for free until July 6th. On that miserable day, a software update will pull the plug and then who knows how much you'll have to pay? Verizon says its $20/GB tethering charge won't apply to 4G LTE phones, but it doesn't state exactly how much it will cost. Oh well, who needs 12Mbps anyway?