DVD Talk Forum - Newbie looking for new TV--what to look for?

Thanks to a somewhat fortuitous turn of events, we actually have some liquid assets, a portion of which I'd like to turn into a new, big TV. Purchase is not very imminent, but for this big a purchase I want to be educated in advance.
Our current TV is a 27" GE that is at least 6 years old, so it's been at least that long since I have seriously looked at the television aisles, and as such, I know little to nothing about all the current specs.
We currently have a satellite receiver, DVD player, VCR, and video game system hooked up to our TV; the sound cable [currently RCA jacks] of the VCR, and the optical digital out of the DVD, are running to a Kenwood HTB home theater reciever.
I recently read an article on CNet or TechTV.com or somewhere, whose final comment was basically something like 'If you haven't upgraded yet, don't--wait for the digital boxes to come standard' or thereabouts. Is this a valid suggestion? How goes the scheduling for the conversion to digital? [I know it was delayed again a year or two ago]
Anyway--my current tv usage is probably 35-50% DVD, 10-20% video games, and the rest regular satellite TV. My DVD interests range from TV show compilations [currently watching Mary Tyler Moore: S1] and anime to scifi/horror/cult/etc movies, and I always look for stuff in the OAR, whatever that may be [last movie watched was SWII: AotC]. Any replacement TV will probably be the 'main' tv, used in the living room [this may change when we move to a bigger house]
I think I'm looking for a big-screen [40"-60"], widescreen TV [or 'monitor' I guess they're called now.] I tentatively also have a dollar cap of about 2k, so no plasma, please ;)
Here are some of my basic newbie questions:
What is the difference, if any, between a 'digital' tv and an 'HD' tv?
I see most of the 'digital' tv's require 'optional set top box'; with a satellite receiver, will I notice a better picture on a digital TV? Will the picture be better on non-digital sources [video games, etc?] Do I have to have a progressive scan DVD player to notice an improvement with DVD's on a digital TV?
I'm pretty much going to want a widescreen TV, right? Many of my DVD's are widescreen, and I'm noticing a lot more regular TV broadcasts are in widescreen also, plus I assume they all have zoom/stretch/letterbox modes for 4:3 sources.
What does all this stuff mean? For instance, Circuit City has the following Panasonic for 1400.
http://www.circuitcity.com/detail.js...4&catoid=-8041
and there's a lot of stuff under the specs that don't mean much to me, even reading their javascript dictionary. At first glance this looked like a good buy to me, but then the Sony above it, model KP46WT500, was 300$ more and only 46"; so it seems either the Sony is overpriced or the Panasonic is underpriced.
Given my viewing habits above, and just to be an educated consumer, which features would be essential to have, which helpful, and which are just sales-speak ['blast processing.']? What brands are generally recognized as having few to no problems, high ease of use, good picture, and long life? And any other information you would care to impart would be greatly appreciated; I know this is somewhat of a vague discussion, but it's more of a 'Help me be an educated consumer' than a 'Which should I buy, model A or model B' at this point.

Thanks for reading this far, and thanks for any advice I may recieve--if I'm going to spend between 1 and 2.5k on a television, it's going to be a decision I agonize over [that's just the way I am], and too much knowledge is never enough.