It will be very interesting to see how Bolden fair before Congress later this week.  I really have some doubts they are going for this new plan.  I rather like the idea of the new commercial space companies but I don't think they are ready for what is being suggested yet.  SpaceX hasn't even flown a Falcon 9 yet.  The have a lot of growth potential in providing the resupply missions for the ISS.  Once that has been demonstrated then they can bring out the mannned version of the Dragon.

One other thought I have on this is that SpaceX, SpaceDev, etc. are small lean companies.  If we get them involved with the NASA HSF bureaucracy it is likely to start them on the way to being a lot less lean like the established space contractors.  I think it might interesting if after SpaceX flies several ISS unmanned supply missions private groups supported developing the Dragon into a crewed vehicle.  Perhaps teams from foreign countries without HSF capabilities might contract with them for trips to the ISS.

As far as NASA goes if we really are going to give up on the real purpose of Constellation to return to the moon, I'd just as soon save the Shuttle.  I've spent a lot of time thinking about alternatives but given the limited funds and timeline it is hard to do better than what we have.  I see the post-Columbia attitude toward the Shuttle as foolish.   

On the other hand the limiting issues on the Ares I/Orion seem to be the J-2X engine that is required for the Ares I's role in the EOR in the Constellation mission.  Couldn't we use a basic J-2 for a near term version to fly to the ISS?