Sgt.Slabber. The production to delivery schedule remains the same as far as I know with multi-year contracts placed two years before each batch of aircraft is delivered, and the first due I think in 2014. I have no idea what the exact IOC is in the case of the UK (I guess should roughly be what S41 said) and will depend much on which version is ordered, but no around 2036 would be if all 138 aircraft are ordered and delivered, which is pretty much what has been planned all along. F-35 training is supposed to begin in the States within the next few years, but enough pilots are supposed to go through the training system for the UK to field a single air wing by the early 2020s. It'll also depend on the development of the F-35 itself, which isn't exactly keeping to schedule.
On the Harrier, even if it had remained in service until 2018, we'd probably still have had a gap of two years to get up to strength to be able to operate an air wing of F-35s, although obviously ten years now is a pretty big gap, but at least they have the sense to put some pilots through training on the F-18 now in the US prior to the start of conversion to the F-35. If that is anything positive to come from what will be announced later today... which isn't really.