QoP, Balanar, Huskar and Nessaj buffs are interesting
TC, Undying, Bat, Ench nerfs were needed
NA needs Dagon (interesting that Dagon got buffed a bit) more than ever to be able to gank alone with his Mana Burn being nerfed, which is really only good against Obsidian late-game or something
and finally Gondar is no longer difficult to click on
I think the nerf to Enchantress may have been a touch heavy-handed considering just how massive 24 STR over the game is.
I really like the nerf to NA, considering just how fucking ridiculous he was as far as early game heroes go. He got just a general rebalance, since he is effectively more powerful late in exchange for less powerful earlier.
Consider that each point of INT gives 13 points of Mana. Effectively, this means that instead of a fixed amount, NA burns ~30% of the target's mana pool. The burn doesn't balance out against original Mana Burn until the opponent has 65 INT, which makes NA much more effective against INT heroes earlygame now. It also might put a little more emphasis on flat mana items for some heroes when facing NA.
In an interesting side note, this means that NA is much less of a hard counter to Skeleton King, now that his Mana Burn is dramatically weaker.
I like the balancing of Anti-Mage. The +80 HP early helps a lot, and by the time it's lategame and the "nerf" has actually begun to take its toll, AM should have stuff like Vanguard to not die like a bitch.
I like the balancing of Heart of Tarrasque. For those who didn't read, it regens 2% of your HP per second when not in battle. This means that Heart of Tarrasque is still the same great tanking item, giving top-notch survivability, but it now gives the bonus that during lane transitions, you can exit middle lane, run over to top lane (or bottom lane), and be solidly healed by the time you get there.
Yet another sidegrade/buff to Curse of the Silent and Battle Hunger. What's the chance it'll take this time?
Among the more interesting small balance changes:
Viper got slowed down, making him slightly less effective at chasing or entering battle (as well as fleeing).
Rhasta has a significantly higher CD on the mass wards.
Nightstalker's Void now slows for half duration during the day (2 seconds). Still not especially useful, but also not entirely useless.
Bear's Entangle is now a Net (allows attacking), but does 50% more damage. This means that Melee heroes have a chance to kill the bear, while ranged heroes can simply attack Sylla and possibly kill him as well.
Lina now has 68 bonus starting mana, making it easier for her to chain her spells early. Slick.
Centaur's Double-Edge now has no manacost, making his mana management much easier. All he needs mana for is Stomp.
Finally, ITEMS
Mjollnir is now a better Strength Hero item than Agility Hero item. It is now Maelstrom + Hyperstone, and gives +70 IAS, +24 damage, and the previous abilities. If you're tired of getting Cuirass for your offensive STR hero, grab a Mjollnir and watch your DPS fly. Also, it now lets STR heroes carry their own awesome Static Charge.
Reworking of all the boots. Boots of Travel get +5 MS, making them solidly the best movespeed item in the game. Power Treads no longer require Gloves of Haste, and give either 10 STR, 13 AGI, or 16 INT, making them optimal caster boots (or boots for people that don't need attack speed). They also give +70 MS now. Finally, Phase Boots traded their armor for Attack Speed, and now require Gloves of Haste. Final boosts are +60 MS, +12 Damage, and +30 AS.
Dagon manacost lowered by 65 at every level, making it significantly less of a drain. Still sucks, though.