Yep ... still a problem. In case anyone at Microsoft was dumb enough to think ignoring it would fix it...
Someone had to actively decide how this was going to work, and intentionally code it so that the additional monitors would blank out. A simple user survey would have shown that tons of users with multiple monitors were customizing in XP (including myself).
As a software person myself, that would have been enough for me to decide to keep the functionality.
But it seems that Microsoft is all around fail at multiple monitors. You can't have the taskbar without a 3rd party app. It's really hard to make backgrounds and screen savers work in a 'nice' way without 3rd party apps. I have to pay money for Actual Multiple
Monitors (which is surprisingly good, but doesn't fix the lock issue). These taskbar issues actually affect productivity and usability. But mostly, I'm seriously annoyed that I have to pay additional money just to get to a state that I would have expected
out of the box. I have my reasons for using Windows over Apple and Linux, but not everyone has the same reasons. If Microsoft could put the effort into the stuff they put out, it might win some people back.
My last company had an office full of dual monitor setups. Our clients walk through that office. Everything is nice and shiny. I have experience in social engineering and usability/user experience, and I can say that subtle things really do leave impressions.
Not just on the clients, but also on the users.
This might be extremely hard to implement .... if XP didn't already do so. But with an example to follow, it should be a piece of cake.
All we need are a few options.
1: Blank additional monitors?
2: Display 1 stretched image or one image per monitor?
3: If 1 image per monitor, duplicate or unique?
And of course, the ability to control what images get used, which should be fine if it follows the existing lock screen example, as that is already configurable.