They've got muck; we've got rakes. TPM Muckraker
Rather, as TPMmuckraker detailed in this post, prosecutors are worried that the Supreme Court will strike down the honest services law, which makes it a crime "to deprive another of the intangible right of honest services." The original Blagojevich indictment alleged he violated the honest services law.
Prosecutors do not want any Supreme Court decision to delay Blagojevich's trial, scheduled for June.
You can read the new indictment here.