can't comment on the veracity of these, but so far this board has been 75% correct (
http://deadwoodstage.proboards34.com)
Ep 509, "Ecotone":• 6/30/2005 - David and Keith get comfortable with their new family life; Claire is shocked to discover she and Ted share a passion for politics; Ruth finds empowerment in the woods; Maggie is forced to make a series of awkward calls; Brenda faces several truths at once; Rico finally "gets" Vanessa; and Nate brings the family together against their will. Written by Nancy Oliver; directed by Daniel Minahan. (source: BTN)
• 7/13/2005 - Maggie (played by Tina Holmes) is embroiled in an intense and ultrasecretive plot twist, which will remain under lock and key until Episode Nine. "In Episode Nine a lot of big stuff happens in the show for everybody. It was interesting how they took their time with a slow buildup, and then suddenly it's, like, 'Boom!' and the season just explodes." (source: Tina Holmes in an interview posted at backstage.com)
• 7/19/2005 - After a bumpy start, David and Keith finally settle into a rhythm at home with Durrell and Anthony; Claire is surprised to find a common interest with Ted; Ruth heads back to nature; and Federico figures out Vanessa's motives. (source: TVG)
Ep 510, "All Alone":• 6/30/2005 - While David attends to family business, Keith makes an embarrassing self-discovery on the job; Brenda is challenged by Nate and answers a hard question for Maya; Maggie gets a door shut in her face; Margaret compares herself to her daughter; Ruth lets Bettina play nurse; Rico and Vanessa decide to protect their future; Claire is comforted by Ted’s squareness; and George makes a speech about love. (source: MC)
Ep 511, "Static":• 6/30/2005 - As David’s fears take over, Keith tries to protect him - and the boys; Billy attends to his sister; Claire goes on a drunken harassment spree and pushes Ted away; Rico pushes for a talk about the business; George tries to help Ruth with Maya; Nate urges Brenda to embrace a taboo; and Vanessa sees the future in a funeral home. (source: MC)
Ep 512, "Everyone's Waiting":• 6/9/2005 - In the season finale, the producers are going to flash forward to the future, showing how all of the Fishers die. (source: Kristin at eonline.com in her weekly chat; posted by Anyone Bueller at TWoP board) (This goes along with the finale casting information I've found for what appears to be various characters shown at different ages (as they get older), or being required to wear aging makeup.)
• 6/30/2005 - In the series finale, David finally embraces a demon; Keith gives “tough love”; Nathaniel talks to his younger son; Brenda delivers early and fights Nate’s negativity; Claire gets an exciting phone call; Ted inspires some sexy photos; Margaret is impressed to see Olivier’s nurturing side; Rico and Vanessa celebrate an investment; Ruth finds consolation in the truth from Maggie; George’s limitations eclipse his intentions; and Claire drives into her future. (source: MC)