As to when these particular models will see their respective updates, that will vary from device to device. And, considering that most of the smartphones are listed in the "Evaluation & Planning" phase, when may prove to be the second half of the year at the earliest.
Motorola advises that smartphone or tablet owners keeping an eye out for the Android 4.0 check out the company's forum. Updated this week, it breaks devices down based on region and on the volume of internal memory. As of today, all devices listed with 512MB RAM are , awaiting a decision.
Given Motorola'sof software updates, I wouldn't over these models. I imagine that Motorola wants to play it safe here and avoid making promises that they may not be able to fulfill.
I'd be curious to hear from some of you who own a Motorola smartphone. How do you feel about waiting until at least the third quarter for your 4.0 update?