Anyone know if there's going to be any format issues between the JVC HM100U and Adobe's CS4 Production suite?

No issues. Premiere Pro CS4 fully supports XDCAM EX.
You can download the CS4 trial from Adobe and test it with my sample MP4 clips (http://www.dvinfo.net/conf/jvc-gy-hm-series-camera-systems/146467-downloadable-35mbps-hm700-clips-testing-your-nle.html).

Here's Adobe's pdf on XDCAM EX workflow (http://www.adobe.com/products/premiere/pdfs/prempro_cs4_xdcam_wfg.pdf). It appears the only mode not supported is the lower-bit rate (SP) 23.98 modes.

I've also tested the Quicktime files on the Mac and Windows versions (as old as PP2) and they work if the XDCAM EX Quicktime component is installed. More info on this in various other threads.

Thanks for the feedback. This camera would be perfect if the focus and zoom weren't controlled by the same ring.