I could be wrong, but I think NVMe support is all about the BIOS supporting it. Primarily you will need an UEFI BIOS capable of booting off of one. Again, those that know please correct me.
Yes, PCI-E SSD using NVMe is the NAND's bright future. Whether you need it is up to you. Most of us don't. SATA-III's 500MB/s IS ALOT OF DATA. Nearly one CD in one second. Support is still burgeoning and products are very few. It's advantage that I like is removing the choke of the SATA controller thus possibly reducing latency.