Ages ago o2 told me that they were phasing them out as they didn't make any money in the forst year of the contract.
I've always been on a 12 monther, till last october when it was up. I didn't take an upgrade (thought I could get it later on) they said not, so according to them i've just been rolling along for the past 10 months or so.
Tbh i'm not getting the best for the money as I never use the minutes up, I was considering pay as you go, but that's pikey.