What options are there for out of band management in desktops?

Like @Michael Hampton says, Intel vPro, and specifically Active Management Technology (AMT), is probably your best solution. AMT is an out-of-band management tool based on an embedded system (microcontroller-based) built into the memory controller hub (see the architecture diagram, as well as lots of other helpful diagrams and tables, in this AMT FAQ) that optionally interacts with the host operating system through agents loaded in the OS (some of the out-of-band functionality needs no agents). There's a boatload of functionality in AMT-- and the DRAC-style remote console functionality you're talking about is in there. It's almost like a superset of IPMI (if you're familiar with that from server applications).