Meh, I don't think it will change much.
What it will do is allow for one or two "wild card" nominations to be thrown in. With the new format, there is no doubt that The Dark Knight and Wall-E would have been included. This would theoretically end the debate over whether or not they are " desrving" or "worthy" of a nomination, but at the same time create the debate about "well, if there were only 5 nominees like their used to be..."
You are right that it is more for the studios. Those who are not Oscar buffs or movie buffs don't remember the losers, no matter if there are 9 or only 4.

I agree with MRPIGG this is not gonna do much...

In fact I hate this idea, and his reasons are the same as mine..

This is so dumb and just for the studios, in the middle of reading it I thought "hey then maybe the smaller independent movies will get some recognition" but when Colin got to his reasoning about how they wont it seems like that probably wont even happen.

This is garbage I mean honestly this is just a way for films who are nominated to get more DVD sales and ticket sales even possibly....its all about making more money and losing integrity and pride, AND PLUS THE MOVIE BUISNESS CONSIDERING THE FAILED ECONOMY ISNT DOING HORRIBLY BAD, I mean actors are still getting paid but some films have been scrapped, but in the end I really think if their trying to make more money somehow it wont do much...

the reader still would have been in there, but who cares. Now films like The Wrestler and Rachel Getting Married have a chance too get in. The Dark Knight and Wall-E would have been in. The next one unfortunately would have been Doubt. This would have been good for last year and great for 2007 when there were so many good films. I don't like this though because it is so obvious the academy is doing this for marketing and trying to get better ratings.

You know I don't hate this idea in and of itself since to me the more frustrating thing about noms is not undeserving movies getting nominations (though that does bug the hell out of me) but deserving films being denied nominations. I think that 10 is probably too many movies but I think 7or 8 nominees is about right. Not that anyone cares but if the rules had been place last year my 10 nominees would have been:
Benjamin Button
Dark Knight
Frost/Nixon
Iron Man
Let the Right One in
Man on Wire
Milk
Slumdog
WALL-E
Wrestler

Terrible, Terrible idea. 5 is a good number. Its supposed to be very selective. Making the number larger will not help independent films, it will hurt them as you say. All this really is for is because of the Dark Knight. Fans went apesh!t that that movie didn't get a nomination and so all those fans probably didn't watch. If the list is increased to ten bigger budget or medium bufget, short of blockbuster films will be in the spot. If a movie like Iron Man is in there then the Academy has lost ALL credibility.
5 represents greatness, films that did something special either with story elements, technical elements or both to advance cinema and highlight what movies can offer other than money. If the list is increased to ten, films that were merley popular and made a lot of money will be put in. It's stupid but I guess if it keeps the academy awards on television it might be worth it in the long run.

I stand by The Reader, it was an excellent movie... But the decision has caused a bit of controversy: http://www.defamer.com.au/2009/06/help-make-a-young-mans-megan-fox-fantasies-come-true/
I hope that it will give both big budget stunners like the Dark Knight a chance as well as underrated gems like In Bruges which slipped under the radar last year.