If it's po$$ible, keep your digital gear and just buy the Rollei system. You can always use the D70 for family snapshots and use the Rollei for "serious" work. The purchase cost/resale-value-after-a-year-or-two ratio of a D70 is NOT going to be anything to write home about. Digital cameras are a lot like new cars - they lose a lot of resale value as soon as they leave the showroom. 6 months later, there's a newer-latest-greatest-model and the resale value drops even more.
The Rollei system is a damn fine camera that will serve you well for many, many years. I wouldn't worry too much about "the death of film", film isn't going anywhere for quite a long time. The Rollei won't become obsolete when a new film stock comes out, you're not limited to the characteristics (and technology) of one image sensor, and the Rollei lenses are fantastic.
Oh yes... about the Canon 1Ds being "better than medium format"... That is pure, marketing bullshit hype. People who "drink the Magic Kool-Aid" might swear that it's true, but they're ignoring the fact that a specific camera is just ONE tool, and there isn't ONE tool that does EVERYTHING best. That's the reason a lot of us have a large variety of cameras - we use the right tool for the job at hand.