Nokia has taken things slow thus far with Windows Phone. Only two handsets have launched with U.S. carrier support thus far — the T-Mobile Lumia 710 and AT&T’s Lumia 900 — and just a few more models have been released internationally. A new leak suggests Nokia may already be planning to ramp up its efforts as Microsoft’s WIndows Phone 8 launch nears, however. According to a series of purported screenshots taken of a Nokia developer tool and published by Nokiapoweruser, Nokia is planning at least three new Windows Phone handsets including the Lumia 1001, Lumia 950 and Lumia 910. The images also references a Nokia 510 and a Nokia Belle 805, but the authenticity of the screenshots has not been confirmed. A similar report last week suggested that the Lumia 910 is listed in Nokia’s RDA developer software, though no mention of the other smartphone models was made at that time.