If you’re a Fusion user (the OS X version of VMware Workstation) then it’s a scary thing to chase OS X betas. More often than not, you’ll get into the new OS and Fusion won’t even launch.
Well, good news with OS X 10.11—starting with the very first beta, released on Monday the 8th, Fusion will run within El Capitan.
I don’t run OS X inside of VMs, so I don’t know if that’s working yet (although I hear it does with a workaround). What I’m speaking of here is the running of El Capitan as the host OS and then running Fusion within it.
One caveat: guest startup takes significantly longer than usual in the beta, like close to 20 seconds before the bar starts loading, so that’s a bit scary at first. But once it does load it seems to work normally.