If your backwards compatible is starting to cut into fan stage 1 and 2 then it wouldn’t surprise me if you get YLOD in the non too distant future. Cheap fixes are increasing the gap underneath the ps3, 3″ appears to be a good distance. You can also stand the ps3 on it’s end which also increases the cooling rate.
next level of preventative maintenance is to get it reflowed – as the ps3 is classed as a toy there is not allowed to be lead in it – so the heatsink has a fairly useless thermal paste – you can get this swopped out.
After that you need to crack open the casing and start drilling holes or set the fan to stage 3 all the time – but then you might as well of bought a xbox360.
If you play games it would also be worth getting a 16gb memory stick and saving your game data every month or so.