I assume in real life that the chance of the Sojourner still being active in any way is nil.

I'm not that familiar with the exact engineering of that rover. Aside from mechanical problems, what would have been the life limit issue of the Sojourner? Insufficient power in winter causing the computer to die? Battery reaching the limit on how many times it can be charged?

It might be possible to create a solar powered rover that would be, mechanical failure or accident aside, electronically immortal. The additional costs and weight would probably be prohibitive.

Can't wait for the nuclear rovers.