I am fairly confident that the PS3 will perform well in terms of sales. And I dont think it has a lot to do with the actual technology. The crap inside the box might sound funky, and help to build the hype, but really the only thing that matters in this case is consumer perception. And that perception, for better or worse, is that the Playstation brand is console gaming. On top of that, the PS3 will work fairly well, and will be comparable to its competitors. This, I think, will be enough when combined with the poor consumer attitude to Microsoft outside the USA and the perception that Nintendo do not have the depth of gaming variety that Sony will have.
I also have to say that Sony have got it generally correct with the styling of the PS3 (and for that matter the other playstations). As their functionality and hence their appeal grew wider, the playstation's styling has become more unassuming. With a product (the PS3) that is now used as a playing device for all kinds of media, Sony have opted for something that looks like it could have come from their range of amplifiers. The Microsoft and Nintendo products have evolved a bit, but still look like toys. After all, kids and teenagers who want a console wont care what it looks like, but there is no way it hell that anything that glows lime green is going to feature on my shelves.