There's an interesting article here at The Register describing the likely development path VMware will take in 2009 and beyond.
Timothy Prickett Morgan tracked down Bogomil Balkansky, senior director of product marketing at VMware, who hinted that only one version of the ESX Server is likely to survive, and the most likely contender will be a renamed ESX 3i-that is, the skinny embedded version that ditches things like a service console in favor of the external VirtualCenter product.
Also, get ready for ESX to double its VirtualSMP capability to span eight x64 cores, with memory quadrupled to 256 GB per virtual machine.
VMware also expects to wade into the issue of applications not being able to take advantage of multicore processors. You can't spread most apps across multiple cores, but you can run them side-by-side on a single virtualized server running multicores. This lets you eliminate multiple footprints while still maintaining decent performance.
There's a lot more in here to dig through, so it's probably worth a look if you're interested in knowing where things are headed.