The SpaceX launch attempt tonight is a big deal. It's the first demonstration by a private company of a capability that could directly lead to private/commercial manned spaceflight. The mission plan is to qualify the spacex system to orbit, rendezvous with the ISS, and then eventually dock. After transferring payload, the module will return to a soft landing on Earth. At least, that's the plan. The whole flight plan has numerous test points and failures at almost any of them would mean no ISS docking attempt. Nobody wants a repeat of the Russian docking collision mishap... If it all works, it's a very short (relatively) step to both routine 2-way cargo missions to the ISS, and routine manned missions to either the ISS or another private/commercial orbital facility. The inflatable habitat modules developed by another company were already proven in orbit, and are on the shelf waiting for the manned launch capability.
The launch is planned for 3am eastern time very early Tues morning. Watch here:
http://www.spacex.com/webcast/The stakes are pretty big. The US has no manned spaceflight capability, period. We could, in an emergency, develop it "overnight" using off the shelf components (with arguably better proven reliability than most WWII aircraft) that are not "man rated" by NASA standards. This would be good enough in a pinch, but it isn't a long term solution so right now we got nothing. But if spaceX has a fully successful mission we are leaping years ahead on the timeline of returning to our status as a spacefaring nation.
Even if it doesn't fully work, they'll still check off test points so even a spectacular failure would still be a "win" from a design-test-fly perspective. Heck, even the aborted launch a few days ago was a huge win for their program because it validated a whole bunch of software and abort procedures.