Technically, it is called lane filtering. On Thursday, March 22nd, Utah's Governor signed H.B 149 allowing motorcycle riders to "lane filter". This will go into effect 60 days from the signing.
However, don't get it in your head that Utah's motorcycle riders will by flying in and out of lanes on the freeway at 80 miles an hour. This is slightly different from lane splitting. Lane filtering happens when vehicles on the road are stopped, and not while they are moving. Motorcycles are only allowed to travel up to 15 MPH while filtering through these lanes.
If you're not aware, Utah drivers are a complete and utter joke. They are oblivious, aggressive, and terrible at pretty much everything on the road. This will be a huge adjustment for Utah drivers and Utah riders, but I think its a great move and a step in the right direction.
For more information on H.B 149, click this.