Ambiguity between names when the only difference is case is not going to help anyone
Ahem. Except me :-)
I do see your point Noel, and it's a good one. In my case, the style is consistent and having case resolve ambiguity simply works. To my coding eyes "FRED" and "fred" are easily distinguished. So yes, I would vote for the option - but I'm not going to get hung up on it.
[edit]
Actually, the more I think about this, the more persuasive Noel's argument becomes. I appear to have unwittingly provided the best argument as to why case sensitivity should NOT be introduced. Sure, it would enforce case consistency, but it would also allow coders like myself to tie themselves in knots with their ambiguous variable names. I feel like I've been hoisted on my own petard here. :-)