Here's the way I see it...
First, Saban's flirtation is directed to recoup any possible value we might get from him, whether that be playing for us or being traded. Assuming (yeah, I know big assumption) that RW wants to come back, is allowed to come back, conforms to the league rules (drug program), gains back the muscle mass he has purportedly lost, works out a contract, etc, etc...here is how I see things happening...
He will come back in SC and have to work his way into shape, while continuing to gain back the muscle mass and get into "football" shape. He will (by all accounts) be suspended for the first 4 games. This will give him another month to continue to work back into shape. When he is reinstated from the suspension, he begins to share time with Brown..more than likely on 1st or 2nd down and mop-up time. This takes the load off of Brown. By late November, RW should be pretty much back to where he should be physically and can handle more of the RB load. Also at this time, Brown is starting to hit the rookie wall (beings his college season would for all intensive purposes be over except the bowl game). This allows Brown to ease into the last month of the season and regain his legs (and hopefully be fresher for the postseason).
Now...by the end of the season, RW has played in about 12 games, with a more substatial role towards the mid and end of the season...he will have shown that he has the desire again and regained respect around the league and some lost value for a possible trade after the season.
Of course, this is all speculation and wishful thinking on my part. This would be the absolute best case scenario for us and for RW...He gives us some quality play during the 2005 season, regains some respect around the league and we can then get better value for him...
This may be the scenario that Saban is thinking of as well. There are certainly a lot of things that are flawed with this situation, but this would be the best case for the Fins (and RW)...he repays the debt to the Fins and has some bargaining value with another team.