I'm definitely a big fan of LED's as well MM. The only problem w/ the design on them is that they have bad viewing angles too. I like to host movie nights w/ lots of people and the side viewing angles while definitely visible, do not have the same color depth that center sitting people do. Plasmas don't have that issue (or at least nowhere near as much if they do).
All that said, I own an LED because it was much cheaper/Samsung gave me a free upgrade to it from the LCD which was even cheaper than comparative plasmas
Oh and PS: a larger screen will not be a negative thing for VRAM as was stated earlier in the discussions. All the TV does is take the 0s and 1s it gets from the graphics card and makes them into pretty colors. That 0,1 --> color processing is handled by the TVs processor and not the GPU of the computer so you'll be fine.
Final edit: But if you MUST have 70" and budget isn't an issue (like at all). Then here's your TV.
http://www.eastcoasttvs.com/Sharp-ELITE-LED-HDTV-p/pro70x5fd.htm I wrote a review on this set when it first came out and docked it something huge for it's motion processing, but that has since been addressed and fixed and is now one of the premiere TVs available. Never have I seen such good color reproduction on a set in all of my days.