I don't read Engadget anymore, I haven't for a while after i noticed there reviews and news were mostly Apple oriented, and BMX has posted on his blog why that is, corruption in Engadget, and the reason why two major journalists for the blog are leaving to start a new one.
Anywho, I highly doubt it will take two - four weeks, the HTC rep tweeted the 17th not long after the news broke about the "conditional" approval. I'm pretty sure HTC was quick to react, then not long after midnight we saw the tweet and facebook post by HTC saying they were announcing the date soon, the first real confirmation we've had since CES. Note: The changes Verizon is requesting is changes in the FUTURE updates, not the current firmware on the device. My guess is this could very well be that they locked 4G to start and are requesting HTC to make an update in preparation to unlock it and are only merely setting up a date to schedule that update and are waiting for HTC to approve that request. (MY theory). MEANING Verizon could still be shipping these to the stores and just have a DO NOT sell order on them until they get approval from HTC and then they will announce the date and they will go on sale.
Since again, the approval is not for what is on the phone NOW, but rather the updates it will receive in the future.
EDIT: Htcsense.com might be getting worked on at the moment since for over a couple of hours now the device list reports an error along with the regions it supports. I'm hoping HTC fully launches the site at CTIA, its still in beta...