Well that's a bummer. So what's to stop the account owner from changing the address back once the buyer pays? Also what if the buyer wants to have the unit hosted with KnC.
Meh, this is not wroth the hassle then.
This are registered and paid for by DeaDTerra:
https://bitcointalk.org/index.php?action=profile;u=40976DeaDTerra pre-ordered and PAID FOR 5 Jupiters, and I purchased (from him) one of the 5. Upon payment, I'll announce the transfer of my interest to the auction winner. Obviously, your ultimate trust is that DeaDTerra acknowledges your ownership of 1 of his 5 units. (He'll take delivery from KNCMiner and coordinate with you)
DeaDTerra will confirm these facts in this thread shortly.