Cataclysm Raid Progression changes (source):
- 10-Man and 25-Man raids will share the same lockout.
- 10-Man and 25-Man raids difficulty will be as close as possible to each other.
- 10-Man and 25-Man raids will drop the exact same loot, but 25-man will drop a higher quantity of items.
- Normal versus Heroic mode will be chosen on a per-boss basis in Cataclysm raids, the same way it works in Icecrown Citadel
- For the first few raid tiers, our plan is to provide multiple smaller raids. Instead of one raid with eleven bosses, you might have a five-boss raid as well as a six-boss raid.
Dealing with Johnny Train Set for 16 hours a week has never been a fun part of raiding. It's been more of a necessary evil to fill out the 25-man roster. In most raids a 25-man team will include Johnnies who are brought along only because raid leaders need to fill out the roster. A lot of raid leaders would not include these players given a solid replacement.
Not to mention the job required to schedule 25 players and deal with players that don't show up consistently, are tardy, just leave without notice, etc. I believe a lot of the "no show" problem is directly related to the current pace of raiding. We all love to play the video games, but when it becomes more like a job then fun, there's a tendency to blow it off every once in a while. A new slower progression requiring less hours per week should lower the "burn out" rate of Raider rank.
If the pace is a lot slower, I imagine their will be an explosion of ALT raiding.