Platinum Predaking was up for pre-order for some time on Amazon, but it has now finally shipped (for anyone who ordered one from there).

For anyone else interested in this figure (looks to be a re-release of the TakaraTomy 2010 version, with an extra sword), it is still available at Amazon for US$120 plus $12.18 shipping.
For under $30 a toy, and they are bigger than a Deluxe, that's pretty good... especially for this Combiner, being the biggest of Gen1.