Great idea for a thread! I often find myself commenting my wishes or predictions for future cover stars in the cover rumour thread and that isn't necessarily the right place for it, so I like this a lot.
I think for US Vogue...
SJP for January: She was shooting with Lindbergh recently, right?
Penelope Cruz for Feb: for Zoolander, although they seem to be going for new faces for Feb in recent years.
Emma Watson for March: based on info from the Cover Rumour Thread.
Lady Gaga for April: most likely a new album next spring, plus she's meant to be on V's spring preview so that's plenty of time between covers.
Gigi and/or Kendall for May: No obvious celeb for the Met Gala theme, and the cover might not even be anything to do with it but 'Fashion in the age of Technology' lends itself well to models I think. Plus the very tenuous link of their 'social media' stardom (even if that theme is very played out.)
Margot Robbie for June: She would be a great summer cover, but maybe July would be a better month for her.
and then in general...
Jessica Alba could very well land a cover.
Kim Kardashian: wouldn't be surprised if she got another cover.
Hillary Clinton is a possibility, she would be great for December but I don't know how likely that is.
Adele is my guess for September. She will have had an epic, record breaking year and will probably fly off the shelves.
Rihanna will probably get another, she could be at any point, although if her album is coming soon then maybe she'll be earlier in the year.
I would love to see Viola Davis and Kristen Wiig also. Plus I think maybe another model cover, probably Kate Moss or Gisele again.