http://en.wikipedia.org/wiki/Skylon_(spacecraft)
Here's the wikipedia article, and I shat bricks reading this:
Once operative, Skylon could potentially lower satellite costs from the current £15,000/kg to £650/kg, according to evidence submitted to the UK parliament by Reaction Engines Ltd.
Now seriously that's nearly 1/23 of the cost of launching satellites alone if it's viable!
The UK also produces a lot of the worlds satellites.
I've been following Skylon for a few years now, and the engine is performing as expected so far. I'm going to the Airshow to watch the engine test - if it's successful, awesome, I get to say I saw a moment (potentially pivotal) in the history of spaceflight. If it fails, Best.Fireworks.Ever.
You should also look at their plans for a Suborbital Liner. They have a Mars concept too.
It's worth noting that the SABRE engine is the grandchild of the HOTOL, and many of the issues have been resolved. The engine profile from the front is similar to the Blackbird in the variable parts, but the cooling solution is fucking genius. It also doesn't need as much thermal protection as the Shuttle, as it'll be much, much lighter on reentry. Also, the Shuttle glided in the way that bricks don't.
First prototype should take off mid-2016. NASA has expressed interest, the ESA has invested and there are a shitload of private investors (Though RE doesn't name them). Shit, the Tories even gave them money, with the promise of more if it works (not quite to the tune of "blank check", though).
From a nationalistic viewpoint; It'll mean a shitload of money for the UK, because we'll have priced fucking everybody out. NASA will probable want the deal they gave us (To-Orbit at cost), and that's fair enough, but China, India, Russia et al will simply be unable to compete in the commercial spaceflight sector, at least not on price.
Fun fact; Skylon is named after an item at the 1950's Festival of Britain, and the fuselage looks similar.
The reason that the Shuttle didn't perform to expectations is because it got fiddled with in the design phase by the DoD and the USAF - they wanted it to be a delta for some reason or another, and they also wanted it redesigned to be able to snatch a spy sat and land in one orbit - this lead to larger wings which were heavier and more expensive and fragile - Columbia would not have been lost in the original design, because that vunerable leading edge wouldn't have fucking been there.