In fact, I own 4 Macs 4 iPods and bought an iPod touch on Jan 12, 2008 3 days too early to get an iPod touch with the 5 additional new apps pre-loaded. see here
I believe it's an marketing BUG in Apple's operation -- it seems their pricing department misunderstood one single business logic -- which is more important $20 or a loyal customer that have spent dozens of thousands dollars on Apple product over the years -- put it straight, I do have $20 -- I donated more than that to software writers and charities.
It is even worse than the $200 price drop of the iPhone which resulted a $100 credit for early iPhone buyers -- this $20 charge for apps specifically identified a special group -- namely the iPod touch buyers bought iPod touch before Jan 15th 2008 -- read "hey stupid buyers, since you can $400 on an unfinished product, apparently you are rich, and should pay $20 more now to get your product complete, Oh, for those smart enough not to jump in and give their hard earned money to us early (so that we can sustain the product line) we'll though in the apps as free so that we can attract people that don't buy unfinished products even if it's from Apple -- read those people don't love Apple as much".
Keep doing this Apple, you will get lots of $20 bills and will loss lots of loyal customers that have came back to Apple and purchased again and again.
$20 is a great income for Apple, it is also an easy way to send away customers that could have spend much more on Apple products.
I'm putting all my Apple purchasing (planed spending is over $2000) on hold until Apple provide free update to existing iPod touch owners so that we can upgrade our iPod touch to the level of the new units sold after Jan 15, 2008