I'm not sure how you manage your priorities, but flushing $700bn down the space toilet when your country has a major economic crisis on its hands isn't quite the best use of $700bn either.
Dollar for dollar, space exploration is some of the best money humanity has ever spent. I won't bore you guys again with teflon and velcro and rivet-less fuselages and all of the other wonders that manned space flight has brought to us. Google does that just fine, but have a think about it every once in a while.
Right now, given our current credit and debt crisis, space exploration (aka extraneous spending) should NOT be at the top of the list. Paying the bills needs to be the focus here, and while space exploration might be the "best money ever spent" as you claim, you might have forgotten that we don't have any money to spend right now.
I wouldn't exactly say the Shuttle platform has failed. Nor would I argue that it's obsolete ... yet (although getting there fast).