Update: Since publishing this story PlayStation Europe has tweeted to confirm that PS3 and PS4 demos of FIFA 15 will be available to download at some point tomorrow:(10th September)
To confirm the #FIFA15Demo is coming to PlayStation tomorrow! We'll make sure you know as soon as it's live on store.— PlayStation Europe (@PlayStationEU) September 9, 2014
Its unclear as to whether the demo will be available on all other platforms today, On Sony’s US Blog it states that a PS3 demo is coming today, but no mention has been made regarding a PS4 version.
Responding to the query on Twitter, EA state however:
The demo comes as a download of 3.07GB and features a match between Liverpool and Manchester City. You can also try out the Ultimate Team mode with some pre-made squads.
The full FIFA 15 game is out on 23rd September in North America and 26th September in Europe and will be available for PC, Xbox One, Xbox 360, PS3, PS4, Wii, 3DS and Vita.