Hubble Space Telescope: Another Outdated Platform?

First, the Hubble is outdated. New adaptive optics are enabling larger mirrors on earth. Combined with interferometry, we're doing a lot more here on earth over the next decade than in space.
The biggest reason, however, has to do with cost: it simply costs more to fix the Hubble than it would be to launch a better scope. And that's it -- end of game. That's not even bringing the shuttle risk bean counters into the argument.
Some neat replacement ideas are coming along, still hampered by expensive cost-to-orbit: reducing this cost needs to be our number one national space goal.
Here's a really cool "unfolding" space telescope idea. I'm not an expert, but this looks like it could save a lot of money. Launch a dozen of these into solar orbit with an interferometry system (biggest cost, probably) and you should have something cheaper than the Next Gen scope from NASA and with better performance in the visible light range.
But there are a lot of devils in the details. One point though -- time-to-market is a critical business function. I wonder why it seems we are running our space systems on "big bang" systems methodologies still, even after the better-faster-cheaper slogans?