This is likely relevant to a few of you out there, anyway. As a very happy user of an Initio Miles UltraWide SCSI board (in my blue&white G3 400 -- ~23MB/sec sustained reads from my Cheetah), I've been frequently contacting Initio in search of drivers for MacOS X PB. (Without the drivers, the board and all devices attached to it cannot be seen by OS X.) Just after Apple started shipping the PB, Initio estimated ~2 weeks for those drivers to be placed on-line. I just came to find out, however, that due to some changes between DP3 -> DP4 -> PB, the drivers are going to take longer I had originally been informed.
It's important to note that Initio officially doesn't support beta OS's so delay or no, anything they provide us before the official release should be looked at pretty-much as a gift to Mac users out there on the edge.
Great hardware, great company.
