The one thing that confuses me about this report is that Spock's mom (Amanda Grayson, shown above played by Jane Wyatt) was human not a vulcan. Although Winona would make a cute vulcan (although she'll have to work on he logic thing):
Winona Ryder joins 'Star Trek'
Actress to play Spock's mother in Abrams film
"Star Trek is beaming up Winona Ryder. Paramount Pictures and director JJ Abrams have set Ryder to play the Vulcan mother of a young Spock (Zachary Quinto). Scripted by Alex Kurtzman and Roberto Orci, the film revolves around the Starfleet Academy days of the crew of the Starship Enterprise. Chris Pine has been set to play Capt. Kirk, Simon Pegg will play Scotty, Karl Urban is Dr. McCoy and Eric Bana will play the villain, Nero."
...by the way for my money the BEST vulcan actress was Kirstie Alley as Lt. Saavik in the Wrath of Khan. Man I'll never understand why they won't let Nicholas Meyer touch Star Trek again!
Snarky Update: Variety revised the story to state that Spock's mom will be human. Although on second thought I do think that Winona would look cute with the pointy ears...