great presentation.
HL/Source engine has a steep learning curve.
the only reason to use the Source engine is for the character models. great control over the faces. everything else about the engine's tools... well, sucks (in terms of ease of use). there's no director tool or a timeline. you basically have to script everything. if you want to see your results (say, a camera move), you have to build your map and run it in the game. it's slow and painstaking. but as the presenter said, you get great results.

The easiest game engine for machinima (by far) is the Unreal 3 engine. it's got a very cool timeline editor (Matinee), that has a director track that lets you switch between cameras. it's got built in depth of field. creating a camera track is as simple as flying it around. you also don't have to compile your map to preview your movie. it's awesome. the only weakness is that there aren't any decent character models. you'd most likely need to learn how to import your own characters. it'd be cool if Mass Effect 2 would ship with a game editor. Epic recently made the Unreal engine freely available. there's also a cool book out there called Mastering Unreal that you should check out (but you can probably find tutorials online just as easily).

anybody ever use the Crytek engine? curious about it.

That was interesting thanks for posting it. We actually did things slightly differently then Ian and the Clear Skies crew but most of what he discussed is exactly what we went through.

It can be a ton of work but the quality is amazing. Thanks to Ian for taking the time to put putting together a nice presentation.