On the official NASA Orion home page, it is still stated that Ares I will deliver the first Orion to the International Space Station by 2014.
However, in all talks I attended at the Kennedy Space Center, the most optimistic date was 2015. And it may take well a bit longer… It is interesting to note that between Apollo and the Space Shuttle program, there also was a six year gap in the human space flight. During that period, NASA had no capability of putting humans in space. It looks like we are up now for at least the same. I just hope they will get Orion off the ground early enough to actually use it for ISS crew ferrying. If the schedule goes beyond 2016, which does not seem unrealistic, ISS crew swaps may possibly only be done by Russian spacecraft. I hope that America will not rely only on these…
Of course, all comes down to budget. I am sure the engineers can do much quicker, but they need to have funds. When the constellation program was announced, it was a lot of vaporware. Most importantly, there was no NASA budget increase. So NASA has already taken money from scientific missions. To go quickly with Orion, additional funds are desperately needed.