In no particular order:
Rip Hamilton
* Only if needed and less likely
Obviously teams with multiple players on this list would have to choose one of them if they decided to take advantage of the amnesty rule.
I doubt Arenas or Hedo and Roy will be on this list, they cost way too much money to cut, their teams would have to be sure they were useless and so not want to pay luxury tax on them.
These player's teams are in such cap hell, it doesn't make sense to buy them out with the intents of cap space, whether future or present, there really aren't many other realistic ways for them to dump further salary to wind up free agent players.
With the Blazers, it could make sense because they could become serious 2012 players, but who's going to come there that isn't coming off a restricted rookie contract?
Plus, again, that's a ton of money to eat.
And that's a reason I think Rashard Lewis is relatively unlikely to be bought out.
Washington is still a couple years away from competing and will be far below the cap even with his contract on their books and in 2012 that it becomes way too much money to spend to get rid of him when he doesn't take them into the tax or really prevent them from any resignings and he can still give you 12 points a game for the life of his deal and a solid veteran presence in the locker room.
So, IMHO, that's the list more or less. I'm sure I forgot a few, but there's not a ton of real impact guys on there.
That's two sided, but for the most part works in teams like ours favor, not many really good players out there signing with the Heat, Mavs, etc. for vet minimum when/if this clause comes into effect.