The reality TV arms race continues: Shakira and Usher are closing deals to join the spring season of The Voice, THR reports. (The show's currently airing its third season; a fourth season will start up anew in February.) And according to Us Weekly, it looks like they'll be replacing Christina Aguilera and Cee Lo Green. Aguilera's been itching to go, and Cee Lo has other projects in the works, so their respective exits aren't major shocks. Shakira and Usher, though, are a little surprising because their names haven't come up in the many, many conversations about filling the American Idol or X Factor judging panels. No word yet on Adam Levine and Blake Shelton's futures with the show, but man, we're almost getting nostalgic for the days of Paula Abdul.