Not really...lol. I am hoping they would release something before April though.
AT&T has the Lumia 1520, 830, 640 and 640XL on the road map. They already pushed a new pre-WM10 firmware last month for the 830 so I am guessing it would only be an OS push for the official upgrade. Similarly the 640 and 640XL have not been receiving any pre-WM10 firmware for unlocked variants so it could be OS only. The 1520 (my device) might get a firmware update before the upgrade since the AT&T variant has an older firmware as compared to other non-AT&T variants.