Summed up briefly, I can say these things for AoC in the state I've experienced it in:
Combat is lovely. Much more hands-on and chunky than we're used to. I foresee plenty of people whining about it, but I for one love it.
If it DOES come out in May, be ready for a buggy and not-quite-finished game. From what I've seen so far, it could easily use several months more on the test bed. But even so, it has captured me utterly. Stuff has "real" sizes, everything is beautifully designed, there is a LOT of different clothing, character customization is great, and it just REEKS of lore. And, keep in mind, that while a buggy and not-quite finished game isn't *optimal*, it is still how many MMO's start. Give it time.
And as for upgrading and giving up on old computers, it has been built to cater to a LOT of different machines. Yes, it will require more power than, say, WoW, but it should run on most machines even so.
The zoning takes some getting used to, but it is no worse than in EQ2, and they actually have good reasoning behind it. Mechanically, it makes it easier to make of course, and allows for more people online. And if you want an actual EXPLANATION why there are zones, it is because these zones are not designed to lie right next to each other like in WoW or LotRO. WoW and LotRO make their worlds tiny by linking everything together. AoC are putting their zones hundreds and thousands of miles apart, with metaphorical travel between them, and leaving the option open for developing the spots inbetween later. I for one love it. Since it is impossible to build the ENTIRE world, I'd rather we focus on the interesting bits, and don't artificially make them smaller than they should be.
I say chin up and let's take it for a spin. I got a very very good feeling about it, and that's what matters most to me really, no matter what people whine about.