After countless rumored release dates, it now seems like Nokia’s Lumia 900 Windows Phone — our favorite product from CES — will finally be available in AT&T stores on April 9th.

Apparently, some AT&T stores already have demo units of the phone available, a WPCentral reader tells the site. AT&T employees have also confirmed the April 9 release to the site, though there hasn’t yet been an official release announcement from AT&T, Nokia, or Microsoft.

The April 9 release makes sense given what we’re hearing from sources as well. The phone is expected to retail for $99 on contract, with online orders starting on April 8th.

The Lumia 900′s specs are killer: It sports a 4.3-inch AMOLED Clear Black display — a big improvement over the Lumia 800′s 3.7-inch screen, 1.4 gigahertz CPU (though unfortunately not dual-core — those Windows Phones are expected later this year), and a front-facing camera for video conferencing. Notably, the Lumia 900 also features a huge battery (1830mah), which should help it survive a day’s worth of heavy usage.

VB Mobile SummitVentureBeat is holding its second annual Mobile Summit this April 2-3 in Sausalito, Calif. The invitation-only event will debate the five key business and technology challenges facing the mobile industry today, and participants — 180 mobile executives, investors, and policymakers — will develop concrete, actionable solutions that will shape the future of the mobile industry. You can find out more at our Mobile Summit site.