Ok, maybe love is a strong word for a character I used for all of an hour (so far). Without any customization options beyond spell memorization, it's difficult to see what the class is really capable of. What magic schools (if any) are going to be available? What will be the upward limit of a wizard's power? When do I get my fireball?
The point here is that there is still way to much left for WoTC to figure out. And rightly so. They've opened themselves up to a dearth of opinions from the entire D&D-playing
That said, there are some things that I think really work and hope will make it into the final edition.
Magic Missile became my go-to spell again, functioning as I would expect it to and dealing enough damage to fell a kobold. Enough said.
I appreciated the simplified nature of spell descriptions. My biggest issue with 3rd edition was the amount of time I spent looking up spells in the PHB or Compendium. Even though we misused Comprehend Languages in an encounter with the kobold chieftain, and assumed it granted the ability to speak the language as well as understand it, the DM was so happy to try out the new skill challenge system that he didn't care. We later figured out a way to make a charisma check against an opposing intelligence save to see if the Kobolds could understand. A simple spell description inspired us to roleplay through a situation that could have easily seen our deaths.
The first wizard I ever played, in 2e, had all of 1 hit point. The DM gave us healing potions at one point, and I gave mine to the fighter because if I ever needed the potion, I'd be dead. 16 was enough to survive a few sling bullets, but still feel a sense of urgency. We haven't yet used the healing or rest mechanics, but I think the lack of easy healing will bring a sense of urgency back to the game. It was assumed that a cleric could keep a party alive no matter what in 4e. Now, in the playtest at least, it's not nearly as certain.
Personally, I'm very happy to get rid of the Eladrin and go back to the older classifications. The name High Elf evokes Tolkien, a sense of history and eternity, whereas Eladrin meant very little to me. Free Spirit, Keen Senses, and Low-Light Vision all felt exactly like the elf of yore, without being a dominating factor in the character build.
Background and Themes
Similarly, these inform the build without being a dominating factor. I flubbed my two lore checks—showing that they aren't ways of getting around role-playing as 3e Bardic Knowledge tended to be—but they are handy tools to move things along when the players are stumped. So long as there are numerous options to inform builds, and not become over-powered, they will only add richness to the game.
I have very few concerns right now, beyond fears over the level of variety in character design (which will likely be unfounded), and spell descriptions either being too ambiguous or too complex. 4e brought a level of clarity to combat situations that I hope they keep, while still encouraging creative applications of a basic set of rules. My own wishes are dangerous, as they assume a sense balance and elegance that won't end up bloated and unwieldy after four years of development, or broken in the hands of power gamers. I tend to belong in the power gamers camp most of the time, though I think in 4e that was easy if not necessary. I'm looking forward to revisiting my roots as an explorer and role-player in Next.
In fact, I'm torn by the fact that I have very little to argue with right now. The advantage/disadvantage system doesn't allow for scaling, and Bounded Accuracy will hard to judge fully until we can see how it impacts the game at higher levels. I want to provide constructive feedback, but I'm pleased with what I see and I'll stay cautiously optimistic about what WoTC will release. I'll leave the vehement arguing to the rest of the denizens of Twitter and the forums.