January is proving to be a really stylish month, with celeb trendsetters setting fashion on fire with an whole series of  covetable looks, from the cool and casual to the full on red carpet looks. This month has seen fantastic looks at Sundance from Kate Bosworth, and with Paris Couture week now attracting the likes of Cameron Diaz and the always impeccable Diane Kruger, it seems that 2012 is looking like a true vintage style year. Here are some more of  the looks making the grade in January. Cameron Diaz has made a glorious return to the fashion front, wearing this beautiful 1950s style polka dot prom dress whilst sitting…