This is standard practice for significant OS upgrades or application enhancements/additions.
You own an old Mac - you have to pay for Leopard (even if you got your Mac just a few weeks before Leopard came out) whilst new Mac purchasers get it for free. You have to pay for iLife '08 whilst new Mac purchasers get it for free.
People have to realise that iPod touch is actually a miniature computer, and as such it is hardly surprising that the traditional rules of OS/application enhancement apply. And, let's just say it one more time - an iPod touch bought a few weeks ago still does everything it could when it was bought. If it didn't fulfill someone's needs, they shouldn't have bought it. Now, faced with the option of extra applications that provide additional functionality people can choose whether it is worth $20 to them and either purchase it and get the apps, or not purchase it and not get the apps.
You keep repeating the same argument and conveniently ignoring certain points every time.
1. The OS is not being upgraded. That's what 1.1.3 is, not the apps.
2. The iPod Touch is not an old machine. It's NEWER than the iPhone. Besides, even with your badly flawed "old Mac" analogy, name one instance where one Mac was denied the same OS features as its contemporary. What does the Mac Mini lack in OS features when compared with the Mac Pro? Does Leopard magically eliminate Time Machine or Stacks if you're running a Mini? There's not a single thing missing. As for iLife, previous Mac buyers got an older version because it 08 didn't exist yet. All these apps existed for the Touch, obviously so because the iPhone had them months before and doubly proven by the fact that many users have loaded those same iPhone apps onto their Touches in the last few months.
3. These are not "extra" applications. They're applications that were REMOVED from the iPod Touch before its introduction that they've finally decided should not be excluded from the Touch, hence their free inclusion from this point on.