The day Apple put a speaker on any iPod, will be the day I boycott the iPod line. The iPod was launched as the 'personal' music player. Very important word there, 'personal':
PERSONAL
–adjective
1. of, pertaining to, or coming as from a particular person; individual; private: a personal opinion.
Ok, in certain situations music is meant to be shared, and in alot of those situations this is great (Concerts, Conferences, Public Performances), but in others it's annoying, irritating and widely disliked. Because we are talking about a mass-market product, you can't stop these people from using a situation like having built in external speakers, irresponsibly - unless, the option isn't there to use, as it currently isn't (Woo Hoo!).
Ever been on the bus and some hard-knock who seems to fancies himself has brought along his portable speakers/phone/mp4 player along for the ride?, blasting whatever junk he likes listening to down your and everyone else's ear-drums, for the entire duration? - if you haven't then you won't understand my argument. Personally, I think the iPod should remain an iPod - meaning, you play what you want, when you want to, wherever you want to, but with headphones. It's your music at the end of the day. Music preference is a matter of personal opinion, and because music has such mass variation, not every piece of music suits everybody's listening preference.
In short, I am 100% against a speaker for the iPod touch, classic, nano and future iPod's, for the above reasons, and I think adding one to the iPhone was a huge mistake.
What the iPod touch REALLY needs is bluetooth, but thats for another thread ...
My .02 cents.
R-Fly