Although this would be nice, it's rather an issue with the guest OS than VMware's capabilities. Think about it. What you request would require VMware to know all the different partition types and file systems. In case a disk has multiple partitions, it would also be required to re-arrange the partitions.
IMO that's a separate task for which either the guest OS itself or dedicated applications may be used.
Well, VMWare already knows a bit about guest partitions. It allows you to mount a NTFS partition, and allows you to shrink the partition (while the VM is powered off).
Just supporting NTFS and FAT32 will cover 99.9% of windows VMWare usage. Then there are only a few popular linux partition types.
Rearranging partitions is seldom done. Most software just allows grow/shrink. It would be very helpful. VMware should conduct surveys of what people want actually...