Mohamed (apologies if I spelt that wrong, I'm on my phone),
See my post here regarding Android 5.x:
http://forums.androidcentral.com/showthread.php?p=2792140
As for the original poster's question, yes, Sony are usually pretty good with releasing updates and upgrades... The catch 22 is the service providers.
See, the way it works is that Sony develop the updates/upgrades, test them and then distribute them once they are happy with the user experience...
Those using generic smartphones/tablets - those that have no (non-Sony) branding at all (usually purchased from Sony directly) - will usually see the updates/upgrades almost immediately...
If you have a smartphone/tablet that is branded and/or supplied by your service provider however, the updates/upgrades will not be made available until your service provider has approved its release, which is often quite a wait.
Some service providers are quick to release updates/upgrades, but you've only gotta stick your head in any Android forum for any manufacturer to see just how often service providers hold back updates/upgrades for long periods of time...
Sent wirelessly from my Sony Xperia Z, using the "Android Central Forums" app...