Yes, I'm running 10.5.2. Before the 1.5.1 firmware, plugging or unplugging USB devices (ipod, iphone, external mouse or keyboard) when the MBP was sleeping would mean a restart every time.
Since I applied 1.5.1 firmware, it has been functioning normally, and I am able to plug/unplug the above devices while the lid is closed and the MPB will come back to life after opening the lid.
So yes, it appears to be fixed.
Note: I applied it less than 24 hours ago, along with several other updates (many ilife apps, and QT, iirc), so I can't say FOR SURE that it was the 1.5.1 firmware that fixed it, but I'm pretty confident that it is.
Since I applied 1.5.1 firmware, it has been functioning normally, and I am able to plug/unplug the above devices while the lid is closed and the MPB will come back to life after opening the lid.
So yes, it appears to be fixed.
Note: I applied it less than 24 hours ago, along with several other updates (many ilife apps, and QT, iirc), so I can't say FOR SURE that it was the 1.5.1 firmware that fixed it, but I'm pretty confident that it is.