Being on the same page on money issues is, IMHO, pretty fundamental to a healthy relationship.
Our arrangement is pretty similar to freebird5825's: his, hers and ours with a relative lack of accountability on the "his" and "hers" parts - both in terms of savings and investing. We have individual savings targets. So long as that target is met, we allow ourselves to splurge on luxuries - but neither of us comes even close to spending all the excess.
Since DW will stop w*orking to become a SAHM at the end of the month, we are revisiting. Current thinking is that I will simply provide her with a lump sum each month for herself + the household bills and leave it to her to spend/save as she thinks fit. The amount is based on a budget we prepared together over a three month period. Having observed her money habits for nearly 10 years I am confident that this will work. I am hesitant to supervise too closely as I do not wish to seem to be a control freak.
I would really struggle to stay in a relationship with someone who had a very different attitude to money.