It's hard for the "Sports Illustrated" swimsuit issue to stand out in aworld of infinite on-demand . . . so they need GIMMICKS. Here's their latest one: Their 50th swimsuit issue comes out Tuesday, and will feature . . . BARBIE. Yes, the doll! Mattel says they wanted Barbie in because, quote, "[she's] under constant criticism about her body and how she looks . . . [this] gives Barbie an opportunity to own who she is."