I don't have an answer for the Fermi Paradox, but I think many of you are vastly overestimating the ease with which we could establish an interstellar colony. Current propulsion technologies just aren't really good enough to move anything of substantial mass such a long distance - especially since we'd need to slow down at the end. There are fundamental limits based on the energy density of our currently available fuels. Sending enough technology to establish a self-sustaining habitat in an unknown and likely hostile environment isn't just expensive - it's damn near impossible with our current level of technology. There's a tradeoff here - you either need vast resources to keep a generation ship alive, which dramatically increases the weight of your payload, or you need very high speeds, which isn't practical for anything but the smallest of payloads.

That's ignoring the fundamental issues with technology mooted by Vinge and others - to set up a high-technology society at interstellar distances you need a surprising amount of stuff and population. This isn't Mars, where we could imagine robotic ships providing a regular supply of high technology goods to keep things going. This is at distances so far that everything needs to be self-sustaining - from materials sourcing to purification to manufacturing to repairs. It requires a lot of people and a lot of equipment. Some people have tried to estimate just how much population would be required to support our current level of technology on Earth, and the numbers are often in the tens of millions. Even if you ruthlessly cut this number down by eliminating positions of marginal importance, you still need an enormous critical mass, especially given the challenges posed by the (likely) hostile colonial environment (which eliminates the possibility of establishing a low tech colony). One could imagine technological breakthroughs in robotics, AI, and nanotechnology that might address this issue, but for now those technologies are science fiction. Self-perpetuating technology simply doesn't exist.

If propulsion gets dramatically better, it will at least be feasible, even if ruinously expensive, to set up a colony. But absent a lot of other fundamental shifts in technology, there's no way it's going to appear to be worth it.