I don't believe Motorola announced anything at MWC. My inclination is that exec's are probably focused on finalizing the merger, rather than announcing any of the potential new devices that are going to be released (at least, until the merger is finalized).
I've been searching almost every day, just to get an idea if Motorola will be releasing another superphone for Sprint. The Photon was placed on the EOL (End Of Life) list, so either that means that they won't be releasing another Motorola superphone or they've got other plans in mind for the future Motorola Android phones offered through Sprint.
Nontheless, these are the "leaks" I've found so far.
Motorola Fighter (w/ Verizon branding)
New Motorola phone pictured, said to be Verizon-bound Droid Fighter
Motorola Blade (US Carrier TBD
...but leaks came from Hong Kong, so possibly another Verizon phone...although, hoping it's possible that Sprint will be going in a similar direction too)
Motorola “Blade” Images Surface – Possible Intel Medfield RAZR Variant?