Considering that KitKat was designed to run on some lower spec'd devices with 512MB of RAM, the Sony Xperia SP should have no problems. The phone features a 4.6 inch screen with 720 x 1280 resolution, and there is a dual-core 1.7GHz Snapdragon S4 Pro CPU under the hood. With 1GB of RAM on board, the Xperia SP should be able to handle the chocolatey goodness of Android 4.4.
Keep in mind that Sony hasn't said that the device won't get the update. The Japanese manufacturer has merely said that it will need to take a look at the phone before making a decision. Previously, as we alluded to above, Sony had said that Android 4.4 would be the next OS version for the model. If you want to sign the petition, you can click on the sourcelink below.
Petition asks Sony to update Sony Xperia SP to Android 4.4
1. Sony says KitKat is coming to Xperia SP
2. Following update to Android 4.3, KitKat update was changed to being under investigation
Thanks for the tip!