Replace the motherboard of my A1200 is highest on my list, althought that won't happen until somewhere in 2009. The current one works ok, but the Indivision flickerfixer doesn't fit (keeps falling off, literally). I also plan to replace the internal 2.5" harddisk with a 4 GB flashdrive.
My A2000 needs a VGA-switch, so I can easily switch between the output of the A2320 flickerfixer and the CV64/3D. After that, I can reinstall it.
My A3000 needs a new harddrive (I have one laying around, just need to put it in), after which I can put back the OS (3.1 or 3.9, haven't made up my mind yet).