exactly how fast the space programme goes not only depends on the technological progress and economic growth, but also the country's determination and allocation of resources. You simply cannot put the space programme always at the very top priority.
The three-step development plan was made when the manned space programme began in the late 1980s. I can feel that there has been change of tune in the past few years. While the second stage (space docking and walking, space lab) will go ahread in the next decade, the third stage which will involve building a permanent 20t space station may never come true. This is mainly because the two previous space stations Mir and ISS have not been very successful, and their effectiveness is now being questioned.
By the time the second stage is completed, which is sometime around 2015, the trend in space exploration may change dramatically. The direction of the Chinese manned space programme may well change too to suit these new development.