Can you change the 6600 Screensaver?

I've currently got a mountain range, with a god awful Orange logo slapped in the corner

Goto to the Nokia service centre and get it flashed to get rid of all the Network inplanted crap, worked on my parent's one.

Or try downloading ScreenSaver from PSiLoc

Does a firmware update automatically remove it, or do I have to ask them specifically to remove the Orange crap?

You can download a psiloc pack (13 apps/games) from my website! Check sig..