I've only gotten to play 2 games with the Druid so far:
The first game I used a Vine Tree for action advantage against a Priest. I won largely by using 2 Thornlashers, 1 in each of the center zones, supported by Vine Snappers. After the first game I wasn't as interested in the Druid as I hoped. She seemed good, but I thought I would just rather play the Beastmaster, and I was uncertain about a number of vulnerabilities (Deathlock, Lord of Fire, strong position control...).
The second game I played, I used a Battleforge and a Vine Tree, and I much preferred the way that played out. My opponent conceded when they realized that I as so far ahead that there was no way he could catch up. There were some clear lessons from this game, such as run more than 2 Rouse the Beast, and I've made some changes to the build based on those lessons.
Here is the current iteration of the build.
Druid [68]
Creatures (34) [12]
1 Galador, Protector of Straywood (5)
1 Tarok, the Skyhunter (3)
1 Kralathor, the Devourer (4)
4 Raptor Vine (12)
4 Thornlasher (8 )
1 Vine Snapper (2)
Equipment (21) [11]
1 Druid’s Leaf Ring (1)
1 Enchanter’s Ring (1)
1 Dragonscale Hauberk (3)
1 Bearskin (1)
1 Elemental Cloak (2)
1 Leather Boots (1)
1 Leather Gloves (1)
1 Veteran’s Belt (3)
1 Moonglow Amulet (2)
1 Wand of Healing (2)
1 Mage Wand (4)
Conjurations (21) [13]
1 Vine Tree (2)
1 Battleforge (6)
6 Tanglevine (6)
3 Mana Flower (3)
2 Corrosive Orchid (4)
Enchantments (14) [12]
1 Harmonize (2)
1 Barkskin (2)
3 Rhino Hide (3)
2 Bear Strength (2)
1 Hawkeye (1)
1 Regrowth (1)
1 Falcon Precision (1)
1 Cheetah Speed (1)
1 Mongoose Agility (1)
Incantations (26) [16]
2 Teleport (8 )
4 Dispel (8 )
4 Dissolve (4)
4 Rouse the Beast (4)
2 Burst of Thorns (2)
Attacks (4) [4]
2 Acid Ball (2)
2 Surging Wave (2)
The plan for turn 1 is:
Turn 1 (19): Vine Tree (Tree Bond) -> Battleforge (2)
After that, things will depend on how aggressive my opponent is. If I can get away with powering for 3 turns, turns 2 and 3 would go something like this:
Turn 2 (12): Druid's Leaf Ring -> Mana Flower -> Mana Flower -> FD Harmonize on Vine Tree (1)
Turn 3 (13): Moonglow Amulet -> Mana Flower -> Reveal Harmonize -> FD Barkskin (no Vine Tree cast) (0)
At that point I'm generating 17 mana per turn with 4 spell actions per turn. I can put Thornlashers in NC and FC and start playing Raptor Vines for offense while my Battleforge plays armor. With Veteran's Belt, all of the armor I can play, and effectively Regenerate 4, the Druid can tank incredibly well. This is approximately how my second game with the Druid went, although there wasn't much need to tank.
If my opponent is rushing me, I can use Battleforge to play armor earlier, and I can start playing creatures earlier. A Vine Snapper guard can help, as can Tanglevine on a creature to prevent early attacks. I'll have to see how well that works out.
Tarok and Galador are there to help with specific problems that plants are not good at dealing with. They gives me a way to deal with Incorporeal objects, creatures that are not vulnerable to Deathlock and fire, creatures with better mobility, an answer to Iron Golems and other heavily armored creatures, answers to flyers, and ways of dealing with Lord of Fire. I still haven't played the Druid against Lord of Fire, so I'll need to see how well that works out in practice. The 2 main cards I need to test this build against are Lord of Fire and Deathlock.
Vine markers are very nice for position control. Placing Vine markers everywhere drastically limits the mobility options of enemy creatures, particularly Fast creatures without Elusive or Flying. I managed to avoid taking an attack from a Ravenous Ghoul in my last game by placing Vine markers in either zone he could travel through to get to me. Plus you can get full board coverage on Tanglevine and vine creatures.
I much prefer Tanglevine to Stranglevine. Stranglevine costs more than Tanglevine, doesn't start out any tougher, and is immediately destroyed by Teleport. Losing a Tanglevine to Teleport is acceptable, but the greater cost of Stranglevine makes this exchange much worse. I'm also not a big fan of the upkeep. Sure, you're paying extra mana to deal direct damage, but I would rather play Ghoul Rot or Magebane for a DoT, as they don't require continued investment.