Component video can in theory do 1080p, but in reality almost every product limits component video to 1080i (example: the Xbox360 can output 1080p via component, but since no HDTV's I've found will accept 1080p via component it is only useful when connecting component to the VGA input of a computer monitor).

All disc players that support scaling are required to limit their component video output of DVD's to 480p when they encounter CSS encryption. There were some early players that ignored this requirement, and some hacks for others (including OPPO's 970HD), but it's rare to encounter such cases.