We'll have to wait and see if there is confirmation of this, but the Tribune is reporting the following:

A source said today that Gov. Rod Blagojevich was taken into federal custody at his North Side home this morning. The U.S. attorney's office would not confirm the information, and a spokesman for the governor did not immediately return a phone call for comment.

UPDATE (9:22): It's confirmed.  You can read the U.S. Attorney's complaint here (PDF).  More from the Tribune:

Gov. Rod Blagojevich and his chief of staff John Harris were arrested today by FBI agents on federal corruption charges. [...]

Blagojevich and Harris were accused of a wide-ranging criminal conspiracy that included Blagojevich conspiring to sell or trade the Senate seat left vacant by President-elect Barack Obama in exchange for financial benefits for the governor and his wife. The governor was also accused of obtaining campaign contributions in exchange for other official actions. [....]

Blagojevich also was alleged to be using a favors list, made up largely of individuals and firms that have state contracts or received taxpayer benefits, from which to conduct a $2.5 million fundraising drive before year's end.

Even Blagojevich's recently announced $1.8 billion plan for new interchanges and "green lanes" on the Illinois Tollway was subject to corruption, prosecutors alleged.

The complaint repeatedly references conversations secretly recorded by federal authorities.