the only thing it does add is the new Thread wireless spec, currently there aren't many devices that use it. I know a couple of the new Nanoleaf essentials products do.
Thread is a fairly robust mesh networking protocol, think of it as a sort of a more reliable bluetooth on steroids, it's better than bluetooth since each device can also forward information to devices that might be out of reach of the one sending the command. (Or also a beefed up z-wave/zigbee if you've dealt with that)
the HP mini functions as an "edge router" meaning it will connect your wifi to the thread network.
if you have thread devices, having the edge router will make your system work better.
if you had the nanolef mentioned above and a mini, the commands would go straight from wifi to thread, without the mini they would need a bluetooth jump from one of your hubs to one of the bulbs before thread took over.
I don't know how useful thread will be to you, it depends on how many Thread devices will become available, and also if you plan on adding devices to your system in the future, or you're pretty much set.
Thread requires certain hardware, so don't expect it to be added via a software update on older devices.
