Will older films be produced on blu-ray or HD?

Just like they colorize many old B&W movies, they may someday try to computer re-engineer old movies to something sharper than it appeared originally. It may not be technologically available as we speak, but in a few years who knows. Might be the only choice if regular DVD is discontinued someday.

I am surprised they did not digitally remove the wires in that Matrix example..

Same for the cost. Digital effects use to be very expensive; now any Joe/Jane with a Apple PC can produce better effects than George Lucas could 5 years ago.

Probably.....Look at all the titles on DVD that pre-date that technology, not to mention the ones that pre-date VHS video tape, (and the ones that pre-date television).