Plan? Encounters? Although I might agree that WoTC's approach to D&D is far from most gamers' ideals, I don't think planning encounters is an issue, you just pick monsters in the XP range of the players and have at it. 1 I don't even look it up in advance.
I'm playing two 4E games right now, both of them I'm both player and DM as we alternate. In one, we're empty shells of characters who fight monsters after monsters. It was what we agreed to do from from the get-go and we're having fun seeing how unkillable our characters are.
2
but then you have one of the DM go: "A dwarf arrives in the room (interrupting our RP), he's quite beaten up. He needs help fighting some monsters that appeared in ruins about a day from here!" 3
1. I think it was possible to have a sandbox type game and still have a little mental list of possible encounters that the players may stumble into. However because I've found 4E sucks hard without miniatures and a battle board I would say that generating an encounter full stop is much more of a pain than 3.5. However I think that making a specific encounter is much better implemented in the early monster manual/dungeon masters guides in 4th in comparison to 3.5. This is just my experience in attempting to run it via maptools, playing face to face when the DM remembers and forgets his battle 'mat' or miniatures.
2. I dropped out of the 4th ed. game I had been in since last September this week. The reason being, among other things, the GM could run a good encounter and make it entertaining 9/10 times but he couldn't handle the story points well and tended to railroad us players. The thing is whenever that 1/10 encounter that no-one was enjoying came up it was absolutely boring and quite frustrating. Which led me to wondering why I bothered going to the game when I could have the same entertainment at the pub with mates or playing videogames with friends round at my/their house.
3. I bet he did this because he had planned an encounter and was set on running it. Which was the main focus of my gripe, it is very bad for starting GMs that can handle story elements a little hamfistedly but will be able to very easily make entertaining encounters time and time again...so they will and only with a lot of encouragement get out of that rut.