Although I do like the mission ideas (human asteroid visit and Mars orbit), the time frame is way too long. Congress will mess this up within 10 years, and that's the real problem. When an organization lives and dies, financially, based on political ebb and flow, there is no way a plan spanning 20+ years is going to work. Period. I'm pretty sure that's why Kennedy wanted the Moon in 10. At least then he could have the chance to oversee the majority of it directly.
Hell, it took just 8 years for NASA to fall under the gun for the Constellation Program. I admit, I didn't like that plan myself, but it's always politicians (who for the most part don't have the foggiest clue about science, engineering, or technology -- other than the on/off switch) who jump in and screw up the process and the flow. Lawyers and bankers have no business regulating that which they have no knowledge.
It would be more prudent to just give NASA HSF a lump sum of $60 billion and give them a more definitive goal set and time line. At least then Congress can't muck it up. Here's what I think is a solid plan of action (based on historical evidence that we can move fast if given the resources). This also includes using international partners AND bringing China, India and other aspiring nations into the mix. Nothing should boost national pride more than WORKING with other nations to do amazing, peaceful things in space.
1. Establish a Trans-Lunar Infrastructure by 2015. Spacecraft (commercially developed), Orbiting fuel depots around Earth and Moon (NASA developed) and dropping supplies on the Lunar surface for phase 2 (both). Work on phase 2.
2. Build Lunar Base for 15 people by 2020. Both commercial and NASA partnerships to be used by NASA and general public scientists (globally as well, but as a rental space).
3. Spend the next 5 years (up to 2025) learning how to maintain, hold, operate and expand the base. 5 years to learn lessons AND inspire. Actually having a base there manned full time would kind of be a big deal for kids.
4. Mars landing by 2030. Use those lessons learned for the next main step, Mars mission. Probably just a landing for a month, depending on the orbital trajectories used, but a mission nonetheless.
At least in this manner, you have something big happening every 5 years. Things are being built, established, done and move forward. Yeah, NASA might need more money after the initial $60 billion, maybe not given commercial and international involvement, but either way at least we'd be getting things DONE! That's the problem with the current way of thinking...will we ever get anything actually done before it's messed with?
As an aside: For NASA doing R&D on advanced systems, I think it's about time we demand the military (Air Force especially) to reveal and employ all the Top Secret crap they've been working on with respect to space based assets. No more cloak and dagger nonsense. It's time to grow up and use what we've already paid for.