Well I couldn't find a thread on these, so forgive me if there is one (the search didn't produce one.) Who all collects these? I myself have Padme, Mace, ARC Trooper and Obi-Wan (my most recent purchase.)
ACME will have the Anakin Skywalker and Darth Sidious keys available at Comic Con.
Anakin is limited to a thousand pieces and you can purchase a max of 3 at Comic Con. He'll be available on www.acmearchivesdirect.com
after Comic Con as well.
Darth Sidious, on the other hand, is limited to 500 pieces and will be 1 per attendee at the Con. 50 will go onsale on ACME's website tomorrow at 10am for those not attending. I see this piece reaching the $200 plateau as soon as Comic Con is over. It's the most limited key thus far.