How do older DVDs look upscaled to HD?

[GOAT]

Alright so I have a 42' Sony with a Sony BD player... I got to thinking and there are some classic titles I dont think will hit blu for many years so I might get the DVDs but am wondering how they will look..

some examples

One, two Three (along with about 10 other Wilder/Lemmon/Mattheau comedies)
Smith goes to Washington
Phantom of the Opera (1925)
They shoot Horses Dont They
To Kill a Mockingbird
War Games (has a re release last yr, did they re master it? is there a way to tell as many of the films had releases early in the decade and then again within the last few years)
Odd Couple, Chinatown (see above, re done for Centenial Release)
Batman Beyond: Return of the Joker
Angels with Dirty Faces
Some Like It Hot
Sunset Blvd
Guess Whos coming to Dinner (also just had a re release)

THANKS