vic20 :
I don't think component has the bandwidth for 1080p, only 1080i ?
Thats correct depending on how it's used, as most component out is YPbPr, and the norm for those TVs is 1080i due to signal quality over longer lengths.
You could push 1080P over YPbPr component, but it will require a TV that supports it (similar to the issue aylafan has with VGA) and then also require good cable quality, because even at 6ft it is very suceptible to line noise.
The most commonly used way to push it (hi res/bandwidth) over component is to use the RGB format which has higher tolerances and doesn't rely on timing differences like the YPbPr, and it essentially mimics BNC connections, just using RCA jacks. There really isn't a limit to these setups, and they can theoreticall under spec carry more info than HDMI 1.3 deep colour (edit - which is a known spec, the cable is limited aroudn that, not sure the HDMI wire spec though), but you need the support from the panel (and output of course).
That's the biggest problem with these things, the physical and spec limitations aren't always the limiting factor, it's the artificially imposed stuff, like TV support, like driver support, app support, crappy DRM, etc that usually limits this.
For HD though the biggest limiting factor (other than the artificial ones) is single-link DVI and even that usually isn't an issue since most of the TVs that accept DVI input allow for reduced blanking as well.
Anywhooo, main thing for most people is check the specs and support for your TV, you are less likely to be limited by your PC than your TV, althugh annoying things like the overlay changes (mainly for windowed/dual screens), the pixel scaling issue, and overscan are often a driver/PC limit, and so if those come into play (more for off resolution TVs) then you should look into that too.