It seems that total experience required per level seems notably lower in the 60+ area. I heard 30% decrease from somewhere or another.

Any news on if this is intended to be a permanent change for the live server during the WOTLK launch? It would be just... fantastic if I could get over with the old content as soon as possible when leveling a Death Knight.

Yes, we're planning on speeding up leveling in the 60-70 range. Keep the feedback coming. We are still adjusting it. Let us know what levels you are in what areas in this bracket.