Got back a few minutes ago, my thoughts are pretty much the same as all of yours.
Palpatine - pure awesomeness. Ian was at his best here. Just didn't like the change in voice pitch after the "transformation."
Visual effects - Best yet! Yoda looked almost exactly like the puppet in terms of lighting. The space battle was pretty cool too.
OT nods - I enjoyed all of them, definately brought back some nostalgia.
Cameos - Hell yeah! Tarkin! Antilles! Boss Nass! PADME'S ******* PARENTS!
Music - I could actually hear a lot of the music! No unnecessary sound effects covering it up! Woohoo! And I loved how the music from other movies fit in with certain scenes, like Duel of the Fates with the Yoda-Sidious fight.
Death of the Jedi - I thought these scenes were done very well. I just wish the Jedi had gotten a tad bit more offense. I know there was a whole bunch of "shock" to it, but they're Jedi Masters for goodness sake! Let them kill at least one Clone!
Grievous - Cough was lame, and he really served no purpose. Why couldn't they just keep Dooku around a little longer instead of adding Grievous? He really didn't show off any great saber skills either.
Droids - WTF? Did the battle droids from E1 have kids who have yet to go through puberty? Really lame. And what was with them showing emotion? "Excuse me!" "You're welcome!"
Duels - All were a bit too short IMO.
THE Duel - I was dissapointed. I felt that there was too much stalling. If Anakin hated Obi-Wan so much, why wasn't he charging at him at all times? It should have been Obi-Wan using his skills and brians to overpower the overly aggressive Anakin, not just what felt like a stroke of luck.
Kashyyk - just felt out of place. I think they could have come up with another way to have Yoda survive. Or made the battle longer.
And one last irking question: Why the hell is Lucas' 9 year old kid allowed to kill like 20 Clones when the leading members of the Jedi Council can't kill squat?
That's just all I can remember off the top of my head right now. I'll definately need to see it several more times to get a better judgment. But I really enjoyed it and I think it still is the best prequel movie.