...and the Marketplace news just keeps on rolling today. Quite a bit considering the darn thing hasn't officially launched yet!
Looks like XDA member Chainfire has already "cracked" the security protection of distribution of paid-for-apps in the Marketplace.
Long story short, when you "buy" a program, you download the .cab file, which automatically installs to main memory. After the installation, the (registered) .cab file gets deleted from your system immediately.
Chainfire has figured a way to circumvent this system, thereby saving the .cab file. One can then simply and illegally re-distribute this file to friends, warez groups etc. Ouch.
Now the good news is Chainfire did not release how he did this (and has no plans to), but considering it took him only "five minutes", it doesn't bode well for long term security. The question is, how else could this have been done while not breaking the OS and keeping things uniform? Could they not pre-register the .cab files with your user ID, like Kinoma offers?