We’ve told you about the L and N series BlackBerry 10 devices. It now truly seems like Research In Motion has answered the age-old daunting question “What will RIM do next in numbering? Have a 10000 device model?”. Nope, they’re going to have multiple models under one series umbrella. Today, we’re excited to reveal the first details of what is known as the BlackBerry 10 M-Series.

Before we start, lets go back in time for a second. The first mention of any BlackBerry 10 device starting with an ‘M’ has been the BlackBerry Milan. The BlackBerry Milan was the rumored slider device, which we heard later was put on hold. Fast-forward to present time and it seems RIM has resurrected the slider project as the BlackBerry M-Series.

What we know of the M-Series is it will sport a 720×1280 screen resolution. Apparently, the BlackBerry L-series will be the only device to rock the high 768×1280 resolution and here on out 720x will be the new standard. The M-Series will likely hit in 2014, as it is planned to release after the multiple N-Series devices (Nevada, Naples, and Nashville).

We’re glad to see RIM still plans a slider BlackBerry. What also has us intrigued is RIM’s new use of alphabetical letters in naming the new series of devices. While we heard the devices received their codenames based on the cities in which their designers took inspiration from, they’re also in alphabetical order. Perhaps there will eventually be a BlackBerry O-Series, P-Series, etc? Time will tell.