WPCentral figures out the 4 resolutions for WP8
Windows Phone 8 Apollo will support these screen resolutions:
Full screen 1:1
The full screen devices will be BlackBerry-esque messaging devices. The low resolution devices will be targeted at emerging markets. Getting apps to fit these screen resolutions will be very easy because the app only has to zoom 2.56x going from lo-rez to hi-rez in either widescreen or fullscreen.
Site logs all over the net are showing WP8 devices with 768x768 screens and 480x480 screens. These devices are using IE10 and have code names like Nokia Fluid and Qualcomm Fluid. The phones are running on Verizon, T-mobile, and AT&T. Judging by DSLReports logs the Verizon model appears to have LTE: