there is no way to change that black out screen, this is a new way being used by nokia to save power, even the mighty Black N82 does the same, and i can see a big difference in the power management...
the cClock solution i think will work, albeit be prepared to have a shorter battery life, there is even a java app that produces a huge analog clock that i have used at one point but i totally dumped that cause it was a power hog,
to remedy this, i just press the left soft button or power button, this will cause the screen to light up for a moment so i can read the status or even the time...