According to Jim Hill(from wdwthemeparks.com):
The primary plan includes Star Wars Land taking over Echo Lake. It would begin at or around Hollywood and Vine and extend to the current location of Star Tours. Components of this land would be as follows
The Mos Eisley Cantina would take the place of the actual lake with Backlot Express being retained as another dining option.
The anchor attraction is expected to be an Endor Speeder Bike attraction that will replace the Indiana Jones Epic Stunt Spectacular. Details of that attraction are below:
50 guests at a time per track, 2 tracks
3 minute ride time
180 degree 3D projection domes will surround the guests
Capacity around 2000 guests per hour
An X-Wing Fighter spinner attraction would be a kid friendly attraction. The wings of the fighters would be able to move in flight. This would likely be built in the area current occupied by the Jedi Training Academy
The Jedi Training Academy would move indoors into the Sounds Dangerous building.
Additionally, they would remove the "movie set" theming. The Ewok Village and AT-AT walker in front of Star Tours would be replaced with full size versions.
Imagineers are pushing for a large streetmosphere presence with interactive components built into the surroundings.
Another plan includes Star Wars Land beginning at the current Star Tours attraction and extending further back into the park in the Muppet*Vision 3-D/Streets of America area. Other things being considered in the other plans include:
The Mos Eisley Cantina replacing Mama Melrose's
A full size Millennium Falcon Walk through
The budget for the total makeover for Hollywood Studios is expected to be in the $600 million to $1 billion range. A meeting in late June of the Board of Directors reportedly resulted in Star Wars content moving forward for both Hollywood Studios and Tomorrowland in Disneyland. Official announcement is unknown at this time. It was initially expected it to be announced at the D23 Expo, however that no longer seems to be the case.