Those PDX - Hawaii flights seem pretty easy to score upgrades on. I am planning on a PDX-OGG trip later this year mostly to secure an easy long-haul upgrade
Despite reaching AS' newest top tier, it seems that there are no systems that actually designate 75K status and 5-day upgrades are NOT in effect.
23Jul2010 AS518 SEA-SNA upgraded approx 96 hours out. I saw U space available, called MVPG reservations line, and the upgrade was handled manually.
26Jul2010 AS515 SNA-SEA Sat in 13D for this one

At 72 hours out, it went from F4 U2 Y0 to F2 U0 Y2. Obviously 2 MVPG upgrades cleared. Mine did not, and the other 2 F seats disappeared shortly thereafter with no U space ever reappearing. At the gate, I was #2 on a list at least a dozen long.
So my mistake on that last one, I didn't have time to call between 72 and 120 hours out to manually request my upgrade, and I thought that 75K's would get bumped up the list automatically. Evidently that is NOT happening yet. For now a 75K is just a regular MVPG who has flown a lot.