Was news to me after reading this Fanpost via Romans12, confirmed at Redskins Insider:

Shaun Alexander, the former NFL rushing champ and MVP, is heading to Washington for a workout on Tuesday, according to sources with knowledge of the situation.

The reason for this is, of course, the injury to Ladell Betts. Fortunately it doesn't appear to be that cereal, with the Jasons reporting "sources with knowledge of the situation" claim this knee injury is of the two-week downtime variety. Without the foggiest idea on what Shaun Alexander would cost the team under contract, I'm unwilling to say signing him to help the team out in Betts' absence is all that good or bad of an idea. I do agree with reader joshp:

when youre bringing in someone and you need him to contribute right away, already knowing the system is a big deal.

(Although I hope he's wrong about Betts being on his way to IR.)

Hindsight being 20/20 and all that, maybe we should've just found a way to keep Marcus Mason on the team? Naw?