I feel some of the pain on the volume button location.
If you're using a case which has a stand feature, in landscape you're more than likely stuck with the volume buttons on the underside. Fortunately I'm using iPhone earbuds which have a built-in volume control, so not too much of a problem when out and about...
When I use mine in portrait I use it "upside-down" as I find having the Home button easier to use at the top, which puts the speaker at the top. I kind of see where the OP is coming from though, using it with the speaker at the bottom tends to muffle the sound if you are resting the iPad on your lap.
Mmm, interesting replies to the OP's original post. Interesting in that it makes you realise the demographic of people who post replies in these forums lately.
I understand your position. If your using the iPad on your lap and you've locked the screen in portrait mode and you suddenly need sound it obviously gets muffled. Easy to flip around and solve but a valid observation all the same.
As an iPhone user going to the iPad there is a natural way you use the iPad and yes, the speaker ends up on the bottom. For the majority of right handed people the speaker would be best positioned along the volume button side but I suppose this wouldn't look as visually pleasing.