true they increase the thickness, which will slightly increase the weight.. but our society isn't bent on thick things. they want slim things. and thats Apple.. they wont add thickness if they dont have to (that's their mentality).. they will have pleasure in slimming things down, but adding thickness somehow irks them and us mentally.
think about it this way.. if you were given the option of having a better graphics card and .2 inches of thickness, would you buy it? here is where an answer of "maybe" comes in. with all these reviews and details of curent gen MBP's, even if they add some thickness, people might hesitate in buying it, because of how their brain thinks.. now if they shave off a .2 inches, more people will buy it, why? slimmer and better..
0.2 inches doesn't seem a lot, but there will be a sig. difference when comparing the two generations. its like the iphones. the first iphone everyone loved, then the next one came out and was sleeker and a little bit slimmer. then the next one and it was different but was a tad bit slimmer. then the current gen iphones are the sleekest, slimmest, and sexiest and yada yada yada.. but if we look at the ratings and the products sold we can very well see that the next gen. model has better sales and a lot of reviewers focus on the design of the device.,
the thing i think the poster was mentioning (the one you replied to) is that if the OD was removed we would have much more room for a MBP 15" like switchable graphics card.. which means the best of both worlds. Nvidia and an i processor.
now i agree that OD's are important but it would be interesting to try the MBP without an OD? it wont be the AIr as it would perform faster and better upgrades and have features that are worthwhile (backlit keyboard, etc)...
apple wants money and to get money that have to satisfy peoples aesthetic desires- making devices look sexier and slimmer. and that is why people have macs and they love it. you look at a PC and they look plain crappy, i mean the trackpad looks weird and some keyboards are horrible.. but you have to admit Apple goes on the looks mostly (and it does have some great features.. but majority on looks?) <= thats me saying as a PC user...