Well for Beth games it's a virtually a necessity.
I spent some time researching the possibility of porting Morrowind to PS3 (using Oblivion) and it just can't be done...well I can't figure it out anyway. I can mod Oblivion, Fallout 3 & NV on PS3 easy enough though, just can't do anything ridiculous on the gfx enhancement side of things because the hardware is too weak.
Skyrim is doable too but I haven't bothered as I have SE on current gen, I'll wait until I have an Xbone so I can actually use external assets![]()