Considering that most people don't even like the horrible design of the 3rd gen, i would hope if they are smart to continue to make the second gen and let us have a choice of which ones we want.
Apple isn't a company that tends to dwell on their past technology. They still make the 1GB version of the 2nd gen, they've just fully discontinued the 2GB model.
It's like wondering why Apple didn't keep the 160GB iPod classic, or offer the 2nd gen nano when there was such outcry at the (subjectively) ugly 3rd gen 'fatty' nano. You can't please everyone, and it's absurd to keep continuing a product that has been pretty much rendered obsolete by a newer version. There were many complaints when they replaced the iPod mini with the iPod nano. Then again when they made the 3rd gen the shape they did. Then AGAIN when they returned back to the original form factor!
The majority of consumers go for what's newer than what's more 'fashionable'. You see people saying 'wow! I just got the new iPod touch!', not 'holy crap, guys, I just got one of the original iPods, look how amazingly thick it is! This mechanical scroll wheel totally pwns your touch screen!'.
It's the same scenario with this. Where the iPod touch's gimmick is that of it's touch screen, Apple's gimmick with the new iPod shuffle is the 'z0mg, no buttons!' factor. And I'm afraid to say that while you are smart enough not to fall into that plot, there are idiots out there that fall for every cheap gimmick.
'
My iPod shuffle pwns
your iPod shuffle because
mine has no buttons...