Working in the legal industry, I can say that there is both a desire and the resources to make HA real. The last firm I worked for runs 2 large 2-node active/passive clusters. One of which was entirely dedicated to the billing system. The other mostly for the DMS but also sharepoint. Towards the end of my time there, they started to implement an off-site HA capability. Basically a simple fail over for the Blackberry database and Exchange server to ensure email would continue.

The firm I currently work for have gone entirely offsite. All SQL servers are running in virtual instances. The SANs are diffed off-site with equal hardware running the same VMs. Downtime for a complete fail over is a few minutes. Because of this, there is no other HA implemented. No clustering or mirroring or replication.