A valid point on scale and margins. PCs are commodity items and there has been a huge race to the bottom for prices. Most consumers won't see or care about the tradeoffs required to support that business model but they do happen and can (not will) have noticeable impacts..

Building your own pc - the trades are your time vs your money and for most people you won't be making your own chips or boards but buying off the shelf configurations. Saves quite a bit of money but it does impose constraints. Eg it is a bit challenging to build your own laptop.

Blue ray -as I said, Apple isn't addressing all market segments. If the market for blue ray gets large enough a third party may step in but if not we have choices.

Lots of choices is a good thing, competition is good too.

-Eric