Re: No Baal Runs!!!
Ok, perhaps I'm simply not explaining myself clearly enough. I'm just going to talk about this as if I'm actually playing it and go through what an average game of D3 should feel like, conceptually, to avoid the Baal Run Problem.
You start up a game of Diablo 3. It will start you in the town that you left off in in the previous game you were in, much like Diablo 2. You will immediately notice that there are several quests around town, for simplicities sake, let's say that there are 3 in this town. (There should be others in other towns, as well as in the game world.) These quests will be drawn from a pool of thousands of available quests, meaning that the quest that you receive will most likely be different then the one you just played, and the combination of quests you get will most certainly be different then any other combination you've gotten previously. (As a note; these quests will be tied to the game, not the player, so all players will receive the same quests from NPCs. This is simply to avoid a ton of problems with large amounts of players in a game, and to focus their attention.)
So the players set out. Keep in mind that the game world itself is always the same. The ravine, or crumbling bridge, or cave entrance will always remain static, so when a quest giver gives you directions to said areas, you will have become quite familiar with them. Of course, there will be potentially hundreds of these kinds of locations all over the game world, and it is possible that the quest you receive in act four might bring you to act one, two, or three. (Assuming four acts) This is, of course, to keep players from simply constantly going to the same exact location over and over and over and over again to wash, rinse, repeat it.
When the player sets out the first thing that he will notice, on the static game world map, is that the monsters/events on that game world map will be extremely varied. A location that was an alter with a talisman, or rune for you in the previous game may now be replaced with an alter that summons monsters, or perhaps there's a merchant there, or a random boss, or a series of traps; any of potentially thousands of encounters my be placed in any one spot at any one time, on this static game world map. The entire time you're on this map, you're encountering new and different things, all of which are viable to drop loot and experience for your character. And this is all just while on the way to do your quest; you're not even fully exploring, you're just going from point A to point B. (Of course there would need to be a discussion about Town Portals and Way Points at this point, but that's another thread entirely.)
So, after already encountering unexpected mobs/events/bosses/chests along the way, the player comes onto his destination, for sake of ease let's just say it is a cave entrance. The last time he was here this cave entrance was where "Jim the Magician" lived. However, in this game world it is housing "Harmony and Melody the Musical Demons!" When you go into the cave, it will be a completely different instance, that has been randomly generated. (So even if you were doing the "Jim the Magician" quest again, the dungeon would still be wildly different then the first time you were through.)
As you head down into the cave you will encounter randomized mobs/bosses/traps/chests/bookcases/ect/ect/ect/, all of which will be valuable to you, as the player, to check out, and see what is in every single nook and cranny of this cave. For all you know an unsearched passage could lead to a huge random boss encounter which will drop the item you've been looking for. Once you find the quest boss, you fight them and then return to town for quest loot, which will be comprised of some pretty hefty stuff. (I imagine that some of the best loot in the game will come from these kinds of quest encounters, or certainly through them)
So, using this style of play you see that the game play is consistently changing and shifting. Players are rewarded for looking in the nooks and crannies of the game instead of encouraged to ignore them in favor of a statically placed boss encounter.
And I'll make this perfectly clear; if you were to put the system in place, that I just explained above, but at the end of act four, on the static world map, put a static boss that dropped the best loot and gave the best XP, then you've simply wasted your developers time. You might as well have simply patched Diablo 2 and called it a day.
I'll say it again, Blizzard has a wonderful opportunity here to create a game where the static bosses are not where the best rewards come from, and rather then rewarding people for going to one spot millions of times, reward them for exploration and discovery.
I don't really understand why anyone would want Baal Runs again.