as a company this is a good move for blizzard. less people doing 25man less demand on the servers, as someone rightly said 10 man cleared in 1 - 2 days and afk rest of week. that would mean people playing less (not a bad thing) but it means blizz wont have to fork out as much on bandwidth so another plan to save some cash.
I can see the positives in the changes but I can also see the downsides. i.e nabs getting awesome kit, alto i,m guessing heroic mode will be for the real raiders. the change will allow the retards to get good kit but same time penalize the good players in having nothing to show for until they get to heroic mode.