I was trying to use the PocketWizard TT5 with the Nikon D4 with my Paul Buff Einstein Strobes and the PowerMC2 and I noticed a slight delay when I hit the shutter release button. It was about a one second delay. I changed up to my Nikon D3S and I had no such problem. I have sent an email to PocketWizard to see if they know of this problem and see if there is a fix on the way.
Here is their response: (net ... net ... it will be a couple months ... July 2012 or so).
Thank you for your inquiry about the D4. There is a lot of new and exciting equipment hitting the market from both Canon and Nikon and we know many of you are hoping to use them with your PocketWizard ControlTL radios as soon as you can. Like you, we’ve been waiting patiently for them to show up (yes, we have to wait for them just like everyone else).
Once they arrive, we start the process to make our system compatible with the new gear. This requires reverse engineering the signals coming up through the hot shoe of the radio, followed by lots of compatibility testing. This is a complex process that can take a fair amount of time and testing depending on how different the new equipment operates compared to earlier models.
Adding compatibility requires a new version of the ControlTL firmware. We are trying to include the D4 compatibility in a future firmware update. With so much new equipment coming out, this may take a couple months and require a few revisions of firmware. Each revision will be released as a beta version that is available to the public first.
We will announce the availability of beta versions and official firmware releases via our Facebook page and
Twitter feed as well as on PocketWizard.com. You may also find some feedback from other photographers who have experimented with the equipment, as many have posted their results.
Here is the link to our Facebook page: http://www.facebook.com/pocketwizards
and our Twitter page: http://www.twitter.com/#!/PocketWizard