Half Life II was released on Nov 16th 2004 and from that point the source engine has been upgraded (and still is)
This is a quote from Wikipedia:
"High dynamic range rendering (2005, Day of Defeat: Source)
Simulation of a camera aperture and the ability to fake the effects of brightness values beyond computer monitors' actual range. Required all of the game's shaders to be rewritten.[14]
Soft particles (2007, Orange Box)
An artist-driven, multiprocessor-optimized particle system. Unlike most such systems, particles are not 'clipped' by 3D geometry.[15]
Hardware facial animation (2007, Orange Box)
Hardware accelerated on modern video cards for "feature film and broadcast television" quality.[5]
Multiprocessor support (2007, Orange Box)
A large code refactoring allowed the Source engine to take advantage of multiple CPU cores on the PC, Xbox 360 and Playstation 3.[16] On the PC, support was experimental and unstable[17] until the release of Left 4 Dead.[18] Multiprocessor support was later backported to Team Fortress 2 and Day of Defeat Source.[19]
Xbox 360 support (2007, Orange Box)
Valve created the Xbox 360 release of The Orange Box in-house, and support for the console, unlike support for the PlayStation 3, is fully integrated into the main engine codeline. It includes asset converters, cross-platform play and Xbox Live integration.[20] Program code can be ported from PC to Xbox 360 simply by recompiling it.[21]
Mac OS X support (2010)
Starting in April 2010, Valve has announced the availability of OpenGL rendered Left 4 Dead, Left 4 Dead 2, Team Fortress 2, Counter-Strike: Source, Portal, Day of Defeat: Source, and the Half-Life series on Mac OS X. All future Valve games will be released simultaneously for Windows and Mac.[22][23] Games will only use Direct3D on Windows, and only OpenGL on the other platforms.
Valve has stated an intent to move Left 4 Dead's AI Director technology into the engine proper,[24] but there is no evidence that this has yet taken place.
In 2009, Left 4 Dead 2 introduced support for Squirrel scripts to be executed in maps.[25] It exists to automate changes to the behavior of existing C++ objects, but cannot extend the game's compiled code."
Most of you (so far) missed a simple point. The game that was run on this laptop, is Portal 2. This title was built upon a version of the source engine which is up to date (all the features from 2004 and up until 2011 are incorporated into this titles source engine).
Not only is the source engine more optimized on this title (compared to the first release of which Half Life 2 was bassed upon, in 2004) but it also incorporates many new features. And to see it running this good on an Intel GPU is, frankly, a good surprise.
You can bash Intel all you like, but they've done some progress on the new chip. Still not on par with the available integrated nvidia / AMD gpu solutions, but it's some progress for intel into the right direction.
NOTE:In 2004 Half Life 2 had support for Direct X 7, Direct X 8 and Direct X 9.0a (I maybe wrong here). So progress was done, as Direct X 7 is no longer supported in the new source engine (correct me if I'm wrong).