It is a known fact that the Motorola Atrix 4G and the HTC Inspire 4G for AT&T came with HSUPA radio turned off by default. We have earlier reported that AT&T might rollout an official Over The Air update to enable the HUSPA radio on both of these devices. And we were right, indeed! Motorola has created a separate page on its website for a software update (v4.1.83) for the AT&T Motorola Atrix 4G. The OTA 4.1.83 highlights some of the important improvements in its change log and first two of them (refer the screenshot below) are suggesting us that it indeed is a fix for enabling HSUPA on the Atrix 4G.
Though we don’t have any official information about the date when the OTA update going to release, we can say it won’t be too long because of the fact that the OTA software update document is already live on the Motorola official website. If you can’t and wait and think that you are geeky enough, you could however enable HSUPA speeds on your Motorola Atrix 4G by hack that has a long procedure, available at XDA forums though we strongly advise you to wait for the official OTA software update to go on air.