If you have an alchemist or especially an inscriptionist, or if you just want to sell herbs as-is on the auction house, leveling through herbalism can be quite profitable. The amount of XP granted per node is pretty decent, especially if you're wearing heirloom gear. I leveled my druid from 75 to 80 solely through herbalism.
At level 75, you'd naturally be in Northrend, and on my server those herbs are more profitable on the whole than Cataclysm herbs. Also, Inscription uses a whole lot of Ink of the Sea, which is milled from Northrend herbs. However, your server may be different, and making tons of Blackfallow and Inferno inks isn't bad either. If you're also leveling alchemy and inscription, still, you'll probably want the Cataclysm herbs. Or maybe you're just sick of flying circles around Sholazar Basin and need a change of scenery. What to do?
Everyone probably knows by now that you can fly yourself to Hyjal and farm before you hit level 80. (If you don't, you'll need EK/Kalimdor flying. As a druid, it's easy to teleport to Moonglade and fly from there, but you can get there from anywhere in Kalimdor.) However, the giant difference in gear and mob health/hitting power can be a huge problem. Luckily, there's a great spot to farm (mostly) Cinderbloom in Hyjal, and until you've quested through the zone, it's almost entirely mob-free. That spot is the area near the Seat of the Chosen in the southeast corner of Hyjal, where the Twilight Cultists will later be hanging out. Until you phase the area, though, the only things you'll see are a few basilisks here and there. They are easily avoided at lower levels, and once you get to 77 or 78 (especially if you're wearing Cata greens) you can take them down without much trouble.
Here's a map of where to go: