It really depends on your location. The different clinics are subscribed and have different capacities. There is a significant increase in the number of referrals to the clinics, as such the time taken to access the care path way and receive HRT has increased substantially.
However 2 years is a long time, and a year to get on a pathway is more probable, following referrals and the assessment period. There is always the option of starting through a private clinic, and waiting to transfer onto the NHS pathway once you've jumped through their hoops. Although that will be expensive, but does give the option of starting sooner on the HRT.
When you have GID confirmed by the NHS, the time until you go on HRT is when you can prove you have started your real life experience (normally proved through ID and other essential documents).
It took me about 8 months to get onto the care pathway, and officially start HRT and the RLE counter for surgery. Oh, and the surgery referral is after 2 years RLE, and with the back log the surgery date following referral is another year. The NHS is struggling

I'm paying for my SRS privately, and will hopefully be in May 2014, so will remove 2 years of waiting on the NHS.
Hope this helps.