Yeah, quite honestly I can see where it'd be fun to work with HL engine based games again. With the newer tech you have all these different scripts, camera scripts, ai scripts, brush scripts, etc. It can get REAL technical and overwhelming for a LD. With Worldcrap or whatever you guys use, it's all about designing rather than programming.
Plus with a HL engine, it's almost like a console now, you develop for it, and you know it's going to work on peoples machines because it's so stable.