Yep, I had the same experience as Jim. This evening I installed the device, which was waiting for me at the Post Office when I got back home.
It works sort-of: the first faff was that it wants to be 192.168.0.10 and if you need to use anything different (which I do) then you have to read the instructions for your computer - not for the device. Since there weren't any instructions for my computer (ever), I told the router about this orphan device, and all was well on that score.
That done, and the software having installed itself about four times (no idea why, it just wanted to), the desktop and the laptop could print through it.
It seemed quite happy to have my high-speed USB hub connected to it, and could see that there were devices there.
Snag one: the USB scanner wasn't in its vocabulary. That was an "oh bother". I didn't connect any of the other potential "shared USB devices" pending further investigation.
The second snag was the faff to use it. Having to start the software, connect, print, disconnect and shut down the software each time proved too much of a pain after about ten minutes.
It's back in its box and the printers and scanner are connected direct to the desktop again. As far as the two computers are concerned, there are two printers in the room and I can "just print" to them as long as the desktop is switched on (which it almost always is).
Anyone want a TP-LINK TL-PS310U, fifteen minutes use, known to be working OK on 1 December 2009?