I don't buy the argument about saving space either as the icon will appear when BT is activated so why not just leave it visible all the time? What happens if the status bar is full and BT is then enabled? Oh, the icon isn't visible even when it's active? Genius! No, I'd rather position it where I can see it all the time and have other less critical icons disappear from the status bar.

Also, I suspect someone at Nokia had a brainwave and realised that the icon can be made to appear in most cases since Bluetooth can be activated by an application or an external device. The trouble is there are a few corner cases where this isn't possible, and I suspect Nokia completely overlooked these cases when redesigning the icon usage. And after reading the bug, I get the impression Nokia don't want to admit they have made a mistake.

As I posted in that bug some time ago, just add a user selectable option (in the Bluetooth control panel) to control the icon visibility and be done with it. This way Nokia don't have to admit that their disappering icon solution is flawed, and users can have the permanently visible icon behaviour if they want it.