Yep - please provide a driver floppy for 32bit XP and 2003 as soon as possible.
Otherwise warn when someone creates a new XP-VM and selects SATA-disks - like you do when a new XP-VM is created and LSI-parallel or LSI-SAS controllers are selected.
At the moment I use 2 LiveCDs for all my VMware Recovery work - one is 32 bit based on 2003 R2 and one is based on Ubuntu 64.
I would not like it if I have to redefine vmdks as SCSI or IDE each time I need the one based on 2003 for VMs in future.
If I were in your shoes I would consider to hide the SATA option when the selected guestOS has no native AHCI-driver - but I hope you dont pick the easy way out 