Jan van Leyden
Adventurer
1) I don't have a problem with this, because the re-training rules allow players to correct for a "bad" decision. I also expect the qualitative differences between powers to become larger with more powers being published.1) All powers are not created equal.
2) You need cards.
3) Use large combats sparingly.
4) I'm wondering if monsters should have less hit points.
5) The DM is the enemy.
6) Magical items are boring.
7. Artifacts are awesome.
8. Skill Challenges aren't working right.
2) I'm undecided on this. As DM I enjoy the fact that power cards put information at the player's place at the table. Before 4e it was mainly my job as DM to adjudicate the players' announced actions, but now they have all the needed information to make sound decisions. On th other hand I see power cards as a big road block for introductory games aimed at not-yet-roleplayers: They catapult the players on to the meta-level, where new players should not spend their time. Due to this I've decided not to use 4e (or D&D at all) for my upcoming introductory game.
3) and 4) Combats seem to run in three phases: Minion Sweeping, Tactical Fight and Boss Confronation. The most interesting phase is the Tactical Fight, wherein monster, encounter, and daily powers are used. Players have to make tactical decisions every round, and the final outcome is not yet clear. When only one opponent is still standing, the grinding begins.
I've switched to a "variable" number of HP for bosses or the last monster acitve in a fight. When all other opponents are down and the last one has used its "interesting" powers, it is quietly elevated to Minion-status: the next hit kills it. Because my players don't know about this, their encounter and daily power use has not changed.

5) The rules are, skill challenges notwithstanding, limited to combat. As PCs are more durable - no 1st level magic user killed by a single blow - the players can react to the situation. Thus, the DM has less need to "save" PCs and can act more like an enemy. But I can and do act as the characters' secret ally nevertheless. When two orcs have separated the mage from the party and cornered him, I still let them miss more often than the die demands.
6) No, not at all! With the model of bonus-plus-power, magic items are way more interesting and variable than ever before.
7) I've never used artefacts...
8) I'm somewhat disappointed with skill challenges as well, having high hopes when Mike Mearls (?) hinted at something as complex as combat rules to handle non-combat situations. Skill challenges work well for simple situations like chase scenes, but less so for complex social interactions, which feel like a duel.
And to add my own points:
9) Cleric College offers only one class for each deity
Clerics of different deities feel very much the same. After just watching a cleric in one encounter, you should be able to name her deity - and without spying on the power cards. This is a very old problem with D&D, I know, but which a new edition offers a chance to correct.
10) Players as bookkeepers
Each player has up to two bookkeeping phases per turn. Part of the results (status changes) should be communicated to the DM as well, which really creates the need for some modern information tracking tools. It is better than with the 3.5e system, but still demands some undue effort.