Given the current HD broadcast standard, availability of HD contents and cost of HD capable devices and accessories, an HDTV capable of 720P or 1080i should suffice for many years. pero kung meron din lang HDMI connectors, of course go for it. the common assumption at the moment is that if a unit has HDMI, it is 1080p capable. I don't know if that is absolutely true without any "but"...but still, a potentially 1080p-capable set is still better than a definitely 1080p-incompatible unit kahit na nasa fetus stage palang ang 1080p contents.
some people say that getting TVs with HDMI will future-proof your TV, which is a good thing considering the cost of the investment...kaso, the technology is really evolving at the moment...major makers are exerting every effort to fix the inherent flaws of LCDs and Plasmas while making their manufacturing process as cost-efficient as reasonably possible, tapos, the likes of Canon and Hitachi are developing even promisingly better flat panel technology (SED). so in my opinion, future-proofed HDTV is quite a fuzzy idea at the moment...kaya just enjoy your current HDTV while you can.
Yes, basically you can only appreciate the difference in resolution of panels kung mas malaki ang TV mo. For instance, 2M pixels panels start from size 37V...sa Sony that would be 40V dahil nga mas mura ang production cost ng Samsung and they can manage to produce 40V sized panels at the same cost as 37V panels of Sharp. sa Japan, ang marketing strategy nila (dahil sa liit ng living rooms dito) is that you can watch daw a 2M panel from a minimum distance of about 1.5 meters and still appreciate the wonder of sharp, clear, and clean high resolution broadcast. but who the hell would allow their children to watch that near on a 37 inch TV or bigger ne??? ako nga if I stay about 2m away from my 32 inch Sharp sumasakit na ulo ko (dahil na rin siguro sa edad).
yung apparent difference between an HD broadcast shown on a 1MP and 2MP panel is that you get more horizontal angle of view when you watch on a 2MP. medyo lumiliit ang tao syempre dahil sa widening. in effect, the current HD standard 1080i signals gets cropped on a 1MP panel, but that's no big deal really because you wouldn't actually know the scenes you're missing unless you have a 1MP and 2MP TVs placed side by side in your viewing room.