Next 10 years golden for space science junkies.

SUN:
ACRIMSAT continues its solar energy measurements, RHESSI solar flares, SOHO vastly increasing our knowledge of SUN activities, SORCE solar energy output, TRACE solar corona, Ulysses heliosphere

Mercury:
Messenger: On its way to providing massive increase in our knowledge about Mercury. Flybys start in 2008.
BepiColombo: launch 2012 arrival 2016

Venus:
Venus Express launched Oct, 2005. Science begins in 2006. Kudos to ESA for Mars Express design reuse to fast track this mission.

Earth: Probes too numerous to list. Needless to say, our knowledge about the Earth from space continues to increase massively as the Terabytes roll in. A few that our currently operating: Aqua for water, Aura for air, Cluster the earths plasma, FAST explore the aurora, GEOTAIL earths magnetotail, GOES earth weather studies, GRACE earth gravity, ICESAT ice sheets, IMAGE magnetosphere, Jason ocean circulation, LANDSAT multispectral study of the continents, POLAR polar magnetosphere, QuikSCAT weather over the oceans, SAGE atmosphere especially aerosols, TERRA global studies, TIMED upper atmosphere, TOMS ozone

MARS:
Mars Global Surveyor, Odyssey, and Mars Expressand the indefatigable MERs continue their science operations.
MRO: The mars assault contnues with MRO science operations to begin in about a year.
Phoenix: due to launch in 2007, and begin science operations on the surface in 2008
MSL: Most sophisticated Rover ever to launch in 2009 and arrive in 2010
EXOMars: launch 2011, arrival 2013 for surface operations and most sophisticated search for Martian life ever
NASA's plans sketchy and under development after MSL...looking forward to their revelation

Jupiter:
We loved you Galileo. We miss you JIMO. Hopefully, JIMO will be refunded as this shaped up to be one of the most fascinating missions ever. Europo certainly deserves a return visit ...is there a way into Europa's ocean?

Saturn:
Casini continues its survey of Saturn and its moons, creating just as many questions as answers.

Uranus
Neptune
We hardly know ye. These are the neglected planets...Thanks Voyagers for even a taste of knowledge about these guys.

Pluto:
New Horizons Probe due to launch in Jan 2006, Arrival in 2015 and onward to Kuiper belt objects in 2016

Asteroids/Comets:
Deep Impact follows up on its spectacular cometary encounter to a possible 2nd encounter with a comet.
DAWN launch in 2006 encounter with Vesta in 2011, encounter with Ceres 2015, talk about cool...visiting large asteroids is it in my book.
Rosetta...asteroids in 2008 and 2010, cometary encounter (main mission including landing) in 2014
Stardust...earth return in 2006 carrying cometary dust from Wild 2

Stars and Interstellar medium:
energetic particles: ACE
Xrays: Chandra, XMM-Newton,RossiXTE
interstellar plasma: CHIPS
ultraviolet: FUSE, GALEX galaxies in ultraviolet
gravity waves: GP-B
gamma rays: HETI, SWIFT, Integral, GLAST (2007 launch)
near infrared and visible light spectroscopy, etc.: Hubble wow
infrared: Spitzer, WISE (2008 launch), JWebbST (2011 launch)
far infrared: Herschel (2007 launch)
microwave background: WMAP, Planck (2007 launch)
ExoPlanetary Hunting: Kepler (2008 launch), SIM (2011 launch)