Judicial Watch has obtained two letters sent to Rod Blagojevich; one from Barack Obama himself, the other from his transition team. PDFs at that link.

Unfortunately, both appear to be form letters sent out after the National Governors Association on December 2, 2008 in Philadelphia. The one from Obama pawns off all contact on Nick Rathod. The other letter is from Valerie Jarrett, John Podesta, and Pete Rouse, and likewise pawns off contact on others in case Blago wanted to "share thoughts". Whether similar letters were sent to other governors isn't known.

The only three things that seem like they might hold promise are:

1. The fact that JW's FOIA request was not complied with in full; Erin Knowles from Blago's office says in the reply to their FOIA request:

This office has no independent knowledge of all individuals who are currently "representatives of the Office of the President-Elect", "representatives of the Obama-Biden Transition Project", or "representatives of the Service Employees International Union". Therefore, if you would specify the names of individuals from who you seek correspondence, we would be happy to conduct a search to determine whether there are any responsive documents.

2. The fact that Obama's meeting with Blago was not in the supposed investigation of his team's contacts:

The President-Elect had no contact or communication with Governor Blagojevich or members of his staff about the Senate seat.

However, the fact that Obama was at the governor's meeting was already known, including with pictures. Perhaps their investigation might have looked better if they had listed all of Obama's contacts with Blago rather than putting it in the legalistic terms above.

3. The fact that Obama's letter starts with the salutation, "Dear Rod". If this was a form letter sent to other governors, did he call them with their first names as well?