When must networks switch to HD? There is no requirement for that to happen. I assume you mean the switch to digital from analog, but that doesn't mean that the content will be in HD. It only means over-the-air broadcasts will switch from analog to digital in February 2009. This deadline doesn't apply to cable, satellite, or whatever these hotels are using.

I've now stayed at three Marriott hotels that have widescreen LCD TVs both in the rooms and the lounge. Only one, Renaissance in Montgomery, AL, had any HD content but even then it seemed very bandwidth constrained which leads to poor HD. My first experience with these TVs was at Renaissance LAX. This TV was such a joke. It was set to vivid mode where the colors and brightness are all out of whack, the sound was in mono, and of course there was no HD.