This means that Promise has not delivered
testing reports to VMWare on ESX 4.0 for your card.
Contact your vendor (Promise) and ask them when the card is going on the
HCL.
That aside - My experience with Promise products is that they develop
them, release bug fixes/firmware/drivers for a few months and then
abandon the product (and release a new shiny card, like the SAS card you
mention). Stay away from Promise is the best advice I can give you.