With the upcoming release of ESXi 7.0, there are a few major changes that are coming about:
William Lam mentions in his blog that 7.0 will no longer support vmklinux drivers, favoring the native driver model. What this means for homelabbers: No more support for community supported 5.x drivers (such as net-r8168, net-r8169, sata-xahci, net-sky2). While storage can be worked around to an extent (drop the drives you would have used locally into a whitebox FreeNAS server and serve NFS/iSCSI instead), networking won't allow you to continue with an installation. If your processor is still supported in 7.0, you'll need to add in a supported NIC, usually in the form of an Intel or Broadcom gigabit adapter. If you have USB 3.0 ports, you should be able to add a USB NIC from the VMware fling, just make sure you inject the driver into your image first.
Which brings me to my next point. Previously, VMware had announced that future versions of particular processors may not be supported in the future. If you're on Westmere-EX (socket 1567) or Sandy Bridge desktop (socket 1155), you'll need to either migrate onto a newer platform, or in the case of the Sandy Bridge desktop, upgrade to Ivy Bridge. I would also speculate that 7.0 will likely state that Ivy Bridge DT, Sandy Bridge-EX and Opteron 4th generation (42/43/62/63XX) series would no longer be supported in the coming >7.0 updates, but should still work on 7.0.
It's disappointing to see the Realtek and Marvell NICs officially dropped from community support, but its completely understandable. These network cards have been on life support since ESXi 5.5 was released. In retrospect, homelab systems using Realtek NICs have been doing so with a driver that was EOL'ed seven years ago. It's high time that we consider upgrading to something a bit more modern!