Thanks for the input
I've skimmed through the Pre-Release Rules Compilation and I have mixed feelings about 4E.
Likes:
1) Spellcasters get to cast spells regularly rather than only once in a while. In previous editions even a wizard with a high intelligence had only a small number of spells per day (especially on low levels) so he got to do his thing only a few times and the rest of the time fight ineffectively with his dagger or crossbow. Now wizards use wizardry in every combat round. This makes them far more interesting to play.
2) Healing Surges. This allows to a degree of independence from a cleric (you could heal yourself), releases the cleric from the annoying "walking bandaide" job, and throws the "15-minute adventuring day" to the garbage-heap of history.
3) Spells don't always come at the expense of each other, so a Cleric could have more interesting spells in her arsenal than just "Cure X Wounds".
4) Less stat-block mess to waste prep time on (apparently). Also, apparently, simpler monster designs and easier monsters to play.
5) AoEs are probably simplified, which is a very good thing.
6) No gnomes. I never liked them and never found a good niche for them, as their niche and flavor seem to overlap with those of dwarves, elves and halflings.
Dislikes:
1) Clerics with offensive evocation-style spells such as Lance of Faith. This breaks very far from the D&D norm of wizards with flashy spells and clerics with more subtle spells.
2) I don't know how complete and playable the game would be with just the 3 first core books. I have neither the budget nor the desire to amass many more books than these, maybe one or two past the 3 first core ones.
3) The increase in amounts of spells per day/encounter/at will, while a great advantage game-wise, might have very bad setting implications, such as upping the overall level of magic.
4) I've heard something about characters forgetting abilities in order to learn new ones. If it's true, that's bad for the suspension of disbelief.
5) Artwork. A lot of what I've seen goes in the "dungeon-punk" or "dungeon-bling" direction, which doesn't fit my D&D style well - I mean, how many mythical/epic/fantasy heroes of renown could you imagine dressing up like that? I prefer more ordinary fantasy art.
6) I fear that the game would be too focused on combat, neglecting fun areas such as dungeoneering, wilderness travel and urban adventures.
7) I'm not sure whether 4E would support small parties (2-3 players) or one-on-one play.
8) I'm yet to see rules about poison/level-drain or other long-term effects that last longer than the encounter itself.