I have not been able to corroborate this, but I just received a MySpace bulletin from the Decemberists that reads as follows:
"With much regret The Decemberists have canceled the remainder of "The Long and Short of It" tour.
One of our band members has been ill for a while but we thought all would be well in time for these tour dates. After a couple shows, though, it has become clear that the illness is much worse than we had initially realized. We need to return home so our friend can mend.
It saddens us to disappoint our fans. We hope everybody understands it is only because of an extreme situation that we had to cancel a tour we've all been excited about doing since the idea was originally hatched.
Our deepest apologies but at this time no plans are being made to reschedule the dates. Ticket holders should seek refunds at point of purchase."