So far we've had:

Tales of Monkey Island Chapter 1 released.
Secrets of Monkey Island remake release(and for only $10!).
MechWarrior 5 announced.
Command & Conquer 4 announced.
Elder Scrolls II: Daggerfall released for free.
MechWarrior 4 and Black Knight expansion released for free.
Street Fighter 4 released.
Trine released(5 star review from Brad).
This is also coming just off a week of ArmA 2, Anno 1404, new Fallout 3 DLC and Battlefield: Heroes.

Ok, so no Half-Life's or Starcraft's were released but look at that list. 2 free classic games, 3 amazing games released, 2 new PC favorite series getting new games announced(Last full MW game was released 9 years ago)  and an aftermath of amazing new games from the week coming into July. Also consider MW and MI series were both thought to be dead and buried years ago.

Also the beta(and final release very soon) of the new Dawn of War 2 patch which is almost like a mini-expansion pack.

Now I know quite a few of the things I listed will be on 360 too, but MW, MI and C&C are all PC first games, started off on PC only and have the most fans on PC so it's still big news.