One which provoked a lot of comment was new licensing terms, which are now per-socket with a maximum virtual memory allowance. The memory cost is new and may force people to re-evaluate how much memory they give to VMs. I think it may be a strategic mis-step on VMware's part, because it changes the dynamic from "VMs are free, and I just buy a new server occasionally" (which leads to a proliferation of VMs, and thus more licenses) to "Every GB of VM costs money, and I need to evaluate whether this new one is worth it." Maish Saidel-Keesing wrote an entry suggesting this was a good thing because it actually gave administrators a cost number ($72/VM at list pricing...)
I wrote an entry for the company blog on vSphere 5's new VASA and Profile-Drivern Storage features.
Another announcement is the Virtual Storage Appliance (VSA--- no confusion there) which exposes local storage on hypervisors as a pool of shared storage, via iSCSI. This means you can do VMotion or other features even without dedicated storage networking. It's pitched for small and medium businesses. Even at that level I tend to think that running diskless is a better option for hypervisors, but it does provide a way to get more of the advanced features (which VMware licenses separately, of course) without as much up-front investment.