As I feared, Bush Jr. announced a new plan for space exploration, containing a terribly misguided “extended human presence on the moon”. I’ve come to recognize this as typical of politicians in general and of Bush in particular.
I fully applaud refocussing NASA and the space program to support sending humans to Mars. However, the science and engineering goals and constraints are best served by Dr. Robert Zubrin’s Mars Direct approach.
I’m not going to try to argue the merits of manned exploration to Mars. That’s a huge subject all by itself. Thankfully, this administration and most of Washington seems to accept the need.
Typical Mars mission plans (including Bush’s) call for the assembly of large spacecraft in orbit (or on the moon), a process which requires multiple launches of heavy lift vehicles. These have been deemed so expensive as to relegate such programs to future generations.1
Commentary I heard on NPR today suggests that we can expect the return to the moon by 2020 and humans on Mars by mid-century, at a cost of $1 trillion. Personally, I plan to see humans land on Mars. In 2050, I’ll turn 81. It’s likely I’ll be alive, but I’d sure hate to miss it because of senility or death.
Dr. Zubrin and others have for years espoused a plan that can get humans to Mars in ten years, for a fraction of the cost, by skipping the moon. There’s no scientific reason to go to the moon, and no good plan for Mars requires mining the moon or using it as a shipyard.
I’ll try to post more information on this subject soon. In the meantime, check out these links:

And I encourage you to read Dr. Zubrin’s book, The Case for Mars: The Plan to Settle the Red Planet.
1Zubrin, Robert M., Practical Methods for Near-Term Piloted Mars Missions.