RIM released the full specs for the BlackBerry 10 Dev Alpha A and BlackBerry 10 Dev Alpha B, you might be thinking now why is this important, since it is just a prototype device? Well for developers it is important for many reasons. First off moving from the OMAP 4460 to the OMAP 4470 (processors) has an impact on performance, in particular for graphics with the new SGX544 graphics chip. The next most important differences are in radio connectivity. Both devices have Quad Band HSPA/UMTS, but the 4 bands supported are slightly different. If you plan on getting a microSIM card for your Dev Alpha, check which bands are required for your carrier.
For example, the Dev Alpha B is limited to EDGE on T-Mobile USA, while the Dev Alph A can get HSPA. Also, the Dev Alpha B has expanded Wi-Fi capabilities, with 5GHz frequency support for 802.11a\n, it supports DLNA, and Bluetooth 4.0 LE.
Full specs:
Source: BlackBerry DevBlog