Also, I just discovered that the Black Mesa Source team have posted an update.

If you don't know about this mod, go and check it out. Its initial goal was to remake Half-Life 1 on the Source engine properly. Valve released "Half-Life: Source" but it was just a weak copy-paste of the old assets onto the new engine; BMS is recreating all the assets from the original game in high-definition, so that it actually looks like a Source game. They've suggested that they might add a few new areas, too, and also that they'll add things like the ability to play through the storyline co-operatively.