Today (2/2) is the day that the HD Pentax 560mm F5.6 lens ($7000) finally went on sale in Japan meaning that we'll soon also be seeing it in the US and elsewhere. Originally expected in the middle December, the lens was delayed by about 6 weeks total.
The 560mm is an extreme-telephoto lens designed for APS-C cameras. It's fully weather sealed and it features a silent and fast DC autofocus system. Pentax recently launched a firmware update for 6 of its cameras in order to get them to autofocus properly with the 560mm lens. According to Pentax engineers at CP+, this lens's autofocus will not be fully supported in live view by older DSLRs such as the K-7 or K-x.
We expect to have a production copy of this lens in our hands soon, so stay tuned for an in-depth review!