Mobile ad network Millennial Media released its latest Mobile Mix report this morning. Android is now officially the number 2 OS on Millennial's network. The Android OS grew another 47% month-over-month. Since January, Android has grown 690%. Android surpassed RIM as the number 2 OS on the network. Apple ad requests increased 24% month-over-month, but are actually down 15% since January. iPad ad requests grew 327% month-over-month, however. Here are the top manufacturers and devices: