Here is what I’ve been able to find so far on the c-span site. They have a link to “Green Party Presidential Candidate” on the right sidebar on their home page:
——————————
http://www.c-spanarchives.org/library/index.php?main_page=product_video_info&tID=5&src=atom&atom=todays_events.xml&products_id=206375-1
Green Party Presidential Candidate
Product ID: 206375-1
Format: Convention
Last Airing: Not Yet Aired
Event Date: 07/12/2008
Length:
Location: Chicago, Illinois
The 2008 U.S. Green Party National Nominating Convention was held in the Chicago Symphony Center. The acceptance speech of their presidential candidate was shown.
——————————
So it looks like it *will* be aired, they just aren’t saying when yet.
Deanna Dee-Dee Taylor 
Road to Washington
For Sunday has been scheduled as:
Sunday at 6:30pm (ET) on C-SPAN
Road to the White House: Libertarian Presidential Candidate Bob Barr & Fmr. Rep. Cynthia McKinney (D-GA)
and Alternatly
This week on Road to the White House, we interview Libertarian presidential candidate Bob Barr. Also, coverage of the Green Party convention in Chicago. Former Rep. Cynthia McKinney (D-GA) is expected to accept the party nomination for president.