I think it will be so useful so people don't have to use xperia m firmware, binaries, and baseband.
Although one sim will work, but it is still useful.
Some countries like Egypt does not get Xperia M single sim in the market.
If you want xperia m you have to buy dual version.
Sent from my C2005 using xda app-developers app
Xperia Mini™ st15i STOLEN
Xperia M dual™ C2005