The new disk driver (libata) wraps in SATA, and IDE drives. Since it is now the default in F7, and since it is not as mature as the old IDE drivers, it sometimes fails to pick them up.
More likely as the machine is pre-production it contains unknown IDE device types. The old kernels (FC6 and earlier) included a generic ISA style fallback driver which FC7 does not and would thus drive unknown chipsets. Thats purely a compile time choice of the kernel builder.
Alan