I'll admit it: De La Hoya is more seasoned and has the more impressive record, but I think he's gotten old. Forget his unanimous decision over Steve Forbes earlier this year; it certainly should haven't been any less. The telling bout was last year against Floyd Mayweather. So I think DLH is pretty arrogant to pit his aging body against Pac's raw speed. It's that speed and tremendous ferocity that will nullify DLH's reach advantage. Six inches is significant by itself, but I don't think it will factor as much as DLH would like. Or hope.
It's expected that a boxer will lose some speed when he moves into a higher weight class, even the tremendously successful weight-shifters like DLH, Floyd Mayweather and Roy Jones Jr. But not Pac. The man is amazing in his ability to put on additional weight yet retain that same lightning speed. We've never seen Pac this heavy, and I don't wonder if it's slowed him down -- I wonder how much stronger he is while remaining just as fast! He's not just pound-for-pound the best boxer right now: additional weight gives him more power pound-for-pound, because of his famous training discipline. Combine that with his reflexes and ferocity, and if they go several rounds, DLH could get too tired. Never mind DLH's left hook. Watch for Pac to could lay him flat with one good hit.
A younger DLH would have been different. He probably could have won, but who knows.