It's exciting to be around for this monumentous day, it's definitely something you'll (hopefully) remember for the majority of your life (at least, I will.)
Background: New Horizons almost never came to be when funding for NASA was severely cut in the early 1990s, and several planned probes to Pluto were ultimately cancelled. However, with a little bit of luck and extreme feats of engineering (and budgeting) marvel, a proposed plan for the New Horizons spacecraft was approved in late 2000.
The New Horizons spacecraft was completed in late 2005, and planned to launch on January 17th, 2006. However, due to weather delays, the probe launched on January 19th, 2006. This was critical to the mission's success, as the proposed trajectory required a tremendous gravitational assist from Jupiter to "slingshot" the probe towards Pluto and arrive on schedule. (I mean, think about that. Physicists and Engineers spent -decades- calculating how to send this spacecraft 7.5 billion km across space to arrive at a chunk of rock half the size of the United States. Holy cow.) If the launch had been delayed by even a few hours on January 19th, the whole mission would've required an additional 3 years to slingshot around Saturn instead of Jupiter (due to orbital paths).
Fast forward 9.5 years and New Horizons has finally reached its closest approach to Pluto, at a distance of 12,600 km (that's about 137,795 football fields), or 1/30 the distance from the Earth to the Moon (That's really close in terms of Space.)
The spacecraft will continue to take high resolution images in all spectrum and conduct multitudes of scientific observations over the next few days of the Pluto and Charon system and the other minor moons of Pluto. It's estimated it will take almost a full year to transmit all of that information back to Earth (all of that information being roughly 16 Gigabytes. That's almost an entire high definition movie being downloaded from the other side of our solar system. Did I mention it's 7.5 billion km away, and transmitting at roughly the rate of 1kb/s, with a 12 hour latency..)
Oh, and here's the latest image of Pluto, received in the early hours of July 13th, shortly before New Horizons went into paparazzi mode (Yes, It's in true color as we would see it up close. Pluto is reddish brown, who'd of thought that?)
Space is cool.
Fun links:
NASA's New Horizons Mission Webpage
JPL's New Horizons Live Feed (images straight from the Space Craft as they arrive in real time!)
New Horizons Twitter Feed (The spacecraft tweets from space. SPACE.
~Aayrl