I spent roughly 3 days to traverse the stretch from 80 to 85.
Starting out in Vash'ir, then Hyjal, Deepholm and dinging 85 about 10 quests into Twilight Highlands, I kept going.
Playing was fun, with the narrative storylines, phased quests and cutscenes adding a good chunk of the roleplaying feeling that I've sorely lacked in the game. Although the bugs I encountered were slightly annoying, that didn't budge my desire to finish off Twilight Highlands and then Uldum at the end.
The changes to the retribution playstyle helped a bit as well, although there are some things that should be addressed, seeing as some of the functionality of the class is highly annoying at times.
I gained 6000 gold (roughly) on my path from 80 to 85, which is not bad.
Cataclysm have been fun so far, much better than what Wrath of the Lich King and The Burning Crusade managed to entertain me with. The grind is still there, but this time, I had fun doing it and didn't even have in mind how fast I was progressing through the levels.
A good job by Blizzard. Let's hope they keep it up that way.