In all the years I've been running VMware - not as many as Nate, but close - I've never had a real reason to look elsewhere. The releases mostly had new features relevant to my environment, and most importantly, they were stable right out of the gate.
The last 18 months have been a shitshow for VMware customers. Bug after critical bug, and it's a total crapshoot as to when show-stopping (data loss, PSODs) problems will get fixed, and fixed for good. The quality of phone support has gone way down as well - the only metric appears to be number of cases closed.
Toss in View (we're VDI for about 95% of our desktops) and the release cycle has become a little shop of horrors. Never used to be this way.
So if VMware is even slightly worried about remaining relevant and keeping long-time customers, they need to get their focus back on quality. There's simply no reason to pay premiums for crap software and support.