Your current root applications still work.
But anything new you try to grant root access won't work.
Yup, you're right. I've verified the apps that had root access prior to my updating to .621 via the OTA upgrade still have root access and any new apps installed after the update that require root cannot access it.
Sorry for jumping the gun and thinking everything was okay when in actuality they were not.
I'm okay for now even without root for new apps since the ones I use are already installed on my phone. I can wait patiently for someone to release a rooted .621 SFB later or another root method for .621.
And in the end, I can always just get a newer phone since 2 of the 5 phones on my Verizon account have been up for renewal for several months now. I've just been waiting for them to offer a quad-core phone (with hopefully an unlocked bootloader). Here's to hoping...