Ok if Samsung will provide Android L, that will be maybe after one year from official release.
I have i9500, and if you care about updates my advice to you to buy Nexus or HTC , Sony or Motorola devices, where those OEM's promised to bring Android L to the current and last year flagships and other devices.
until now we didn't got the Kitkat 4.4.3
, where Sony, HTC & Moto already provided it to many of their devices.
Samsung just know how to release 1000 device in a year and forget all about them.
If you want updates keep away from Samsung.