Half-Life 3 was allegedly trademarked in Europe last week, and it's not come to light that the whole thing was a prank.
When will this dance of rumour, speculation and spin end you ask? Whenever Valve actually talks about the game, probably.
Interestingly, I bought a bag of oranges from the local grocer's yesterday and pulled this out:
WHAT DOES IT ALL MEAN?
Are you growing impatient? Speak below.