It appears that the Hubble might end up as collateral damage from the recent collision between an Iridium and Russian satellite. Without another service mission, the Hubble may meet its end within a year or two.
The collision has sent more than 600 pieces of debris whizzing around the Earth at 28,000 kph. At those speeds, shards can take out a spacecraft (and you don't even want to think about what it could do to astronauts on a spacewalk). NASA has calculated the chance of a catastrophic impact at around 1 in 185—just below their 1 in 200 threshold. A decision on whether or not to progress with the Hubble repair mission in May is expected to come down within the next week or two. [Discovery via Wired]