Update:
It was later revealed that the trademark that was filed was a fake and was removed from the listing. The original article can be found below.
On September 29, 2013, Valve filed a trademark for “Half-Life 3” in Europe. There are two classifications listed for this trademark. the first being for “Computer game software”. Although the prospect of the trademark being filed period is rather interesting, the most interesting part of this trademark is it’s provision for “On-Line Entertainment”.
Could Valve be teasing a multiplayer component for the next Half-Life?

Another trademark filed in Europe back in July is for the Half-Life symbol.
After some research, I have learned that trademarks are not something you can file as a precautionary measure in case someone tries to release something with that name. A trademark is not something you file just to ‘screw’ with people — you HAVE to use it. In Europe, you can file a trademark and have up to three years (after extension) to use it in an advertisement before the trademark runs out. This could mean that we might not see anything from Valve in terms of Half-Life 3 for about three years.

Half-Life trademark listing.
What could this trademark mean?
Are your hopes for Half-Life 3 raised? Have you grown tired of waiting for a third installment? Post your comments below. As always, thanks for letting Stagger’d inject you with knowledge!